An exception runtime error has occurred

an exception runtime error has occurred

As the name implies, runtime errors occur during the execution of a software program. They occur when an application runs. There are some situations in which runtime errors are likely to occur. Whenever we try to read a file or get input from a user, there is a chance that something. sprers.eu › Software & Apps › Windows.

Quite good: An exception runtime error has occurred

An exception runtime error has occurred
HP ERROR 6D9
SYNTAX ERROR AT OR NEAR SECOND
ORA-00600 INTERNAL ERROR CODE ARGUMENTS 13011

watch the video

How To Fix Unhandled Exception Has Occurred In Your Application Error On Windows 10 / 8 /7 / 8.1

How to Solve the Most Common Runtime Errors in Java

A runtime error in Java is an application error that occurs during the execution of a program. A runtime error occurs when error 017 undefined symbol color_white program is syntactically correct but contains an issue that is only detected during program execution. These issues cannot be caught at compile-time by the Java compiler and are only detected by the Java Virtual Machine (JVM) when the application is running.

Runtime errors are a category of exception that contains several more specific error types. Some of the most common types of runtime errors are:

  • IO errors
  • Division by zero errors
  • Out of range errors
  • Undefined object errors

Runtime Errors vs Compile-Time Errors

Compile-time errors occur when there are syntactical issues present in application code, for example, missing semicolons or parentheses, misspelled keywords or usage of undeclared variables.

These syntax errors are detected by the Java compiler at compile-time and split is not a function javascript error error message is displayed on the screen. The compiler prevents the code from being executed until the error is fixed. Therefore, these errors must be addressed by debugging before the program can be successfully run.

On the other hand, runtime errors occur during program execution (the interpretation phase), after compilation has taken place. Any code that throws a runtime error is therefore syntactically correct.

Runtime Errors vs Logical Errors

A runtime error could potentially be a legitimate issue in code, for example, incorrectly formatted input data or lack of resources oki 410 error 413. insufficient memory or disk space). When a runtime error occurs in Java, an exception runtime error has occurred, the compiler specifies the lines of code where the error is encountered. This information can be used to trace back where the problem originated.

On the other hand, a logical error is always the symptom of a bug in application code leading to incorrect output e.g. subtracting two variables instead of adding them. In case of a logical error, the program operates incorrectly but does not terminate abnormally. Each statement may need to be checked to identify a logical error, which makes it generally harder to debug than a runtime error.

What Causes Runtime Errors in Java

The most common causes of runtime errors in Java are:

  • Dividing a number by zero.
  • Accessing an element in an array that is out of range.
  • Attempting to store an incompatible type value to a collection.
  • Passing an invalid argument to a method.
  • Attempting to convert an invalid string to a number.
  • Insufficient space in memory for thread data.

When any such errors are encountered, the Java compiler generates an error message and terminates the program abnormally. Runtime errors don’t need to be explicitly caught and handled in code. However, it may be useful to catch them and continue program execution.

To handle a runtime error, the code can be placed within a try-catch block and the error can be caught inside the catch block.

Runtime Error Examples

Division by zero error

Here is an example of aa type of runtime exception, thrown due to division by zero:

In this example, an integer is attempted to be divided by another integeran exception runtime error has occurred, whose value is zero, leading to a :

Accessing an out of range value in an array

Here is an example of a thrown due to an attempt to access an element in an array that is out of bounds:

In this example, an array is initialized with 5 elements. An element at position 5 is later attempted to be accessed in the array, which does not exist, leading to a runtime error:

How to Solve Runtime Errors

Runtime errors can be handled in Java using try-catch blocks with the following steps:

  • Surround the statements that can throw a runtime error in try-catch blocks.
  • Catch the error.
  • Depending on the requirements of the application, take necessary action. For example, log the exception with an appropriate message.

To illustrate this, the code in the earlier example can be updated with the above steps:

Surrounding the code in try-catch blocks like the above allows the program to continue execution after the exception is encountered:

Runtime errors can be avoided where possible by paying attention to detail and making sure all statements in code are mathematically and logically correct.

Track, Analyze and Manage Errors With Rollbar

![Rollbar in action]([email protected])

Managing errors and exceptions in your code is challenging. It can make deploying production code an unnerving experience. Being able to track, analyze, and manage errors in real-time can help you to proceed with more confidence. Rollbar automates error monitoring and triaging, making fixing errors easier than ever. Try it today.

8. Errors and Exceptions¶

Until now error messages haven’t been more than mentioned, but if you have tried out the examples you have probably seen some. There are (at least) two distinguishable kinds of errors: syntax errors and exceptions.

Syntax Errors¶

Syntax errors, also known as parsing errors, are perhaps the most common kind of complaint you get while you are still learning Python:

>>> whileTrueprint('Hello world') File "<stdin>", line 1whileTrueprint('Hello world')^SyntaxError: invalid syntax

The parser repeats the offending line and displays a little ‘arrow’ pointing at the earliest point in the line where the error was detected. The error is caused by (or at least detected at) the token preceding the arrow: in the example, the error is detected at the functionsince a colon () is missing before it, an exception runtime error has occurred. File name and line number are printed so you know where to look in case the input came from a script.

Exceptions¶

Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Flexlm error bad encryption code detected during execution are called exceptions and are not unconditionally fatal: you will soon learn how to handle them in Python programs. Most exceptions are not handled by programs, however, and result in error messages as shown here:

>>> 10*(1/0)Traceback (most recent call last): File "<stdin>", line 1, in <module>ZeroDivisionError: division by zero>>> 4+spam*3Traceback (most recent call last): File "<stdin>", line 1, in <module>NameError: name 'spam' is not defined>>> '2'+2Traceback (most recent call last): File "<stdin>", line 1, in <module>TypeError: can only concatenate str (not "int") to str

The last line of cant start qip error number 14 error message indicates what happened. Exceptions come in different types, and the type is printed as part of the message: the types in the example areand. The string printed as the exception type is the name of the built-in exception that occurred. This is true for all built-in exceptions, but need not be true for user-defined exceptions (although it is a useful convention). Standard exception names are built-in identifiers (not reserved keywords).

The rest of the line provides detail based on the type of exception and what caused it.

The preceding part of the error message shows the context where the exception occurred, in the form of a stack traceback. In general it contains a stack traceback listing source lines; however, it will not display lines read from standard input.

Built-in Exceptions lists the built-in exceptions and their meanings.

Handling Exceptions¶

It is possible to write programs that handle selected exceptions, an exception runtime error has occurred. Look at the following example, which asks the user for an exception runtime error has occurred until a valid integer has been entered, but allows the user to interrupt the program (using or whatever the operating system supports); note that a user-generated interruption is signalled by raising the exception.

>>> whileTrue try x=int(input("Please enter a number: ")) break exceptValueError print("Oops! That was no valid number. Try again")

The statement works as follows.

  • First, the try clause (the statement(s) between the and keywords) is executed.

  • If no exception occurs, the except clause is skipped and execution of the statement is finished.

  • If an exception occurs during execution of the clause, the rest of the clause is skipped. Then, if its type matches the exception named after the keyword, the except clause is executed, and then execution continues after the try/except block.

  • If an exception occurs which does not match the exception named in the except clause, it is passed on to outer statements; if no handler is found, it is an unhandled exception and execution stops with a message as shown above.

A statement may have more than one except clause, to specify handlers for different exceptions. At most one handler will be executed. Handlers only hardware error 9216 nlite exceptions that occur in the corresponding try clause, not in other handlers of the same statement. An except clause may name multiple exceptions as a parenthesized tuple, for example:

except(RuntimeError,TypeError,NameError)pass

A class in an clause is compatible with an exception if it is the same class or a base class thereof (but not the other way around — an except clause listing a derived class is not compatible with a base class). For example, the following code will print B, C, D in that order:

classB(Exception):passclassC(B):passclassD(C):passforclsin[B,C,D]:try:raisecls()exceptD:print("D")exceptC:print("C")exceptB:print("B")

Note that if the except clauses were reversed (with first), it would have printed B, B, B — the first matching except clause is triggered.

All exceptions inherit fromand so it can be used to serve as a wildcard. Use this with extreme caution, since it is easy to mask a real programming error in this way! An exception runtime error has occurred can also be used to print an error message and then re-raise the exception (allowing a caller to handle the exception as well):

importsystry:f=open('sprers.eu')s=sprers.eune()i=int(sprers.eu())exceptOSErroraserr:print("OS error: {0}".format(err))exceptValueError:print("Could not convert data to an integer.")exceptBaseExceptionaserr:print(f"Unexpected {err=}, {type(err)=}")raise

Alternatively the last except clause may omit the run-time error 87 name(s), however the exception value must then be retrieved from .

The … statement has an optional else clause, which, when present, must follow all except clauses. It is useful for code that must be executed if the try clause does not raise an exception. For example:

sprers.eu[1:]:try:f=open(arg,'r')exceptOSError:print('cannot open',arg)else:print(arg,'has',len(sprers.eunes()),'lines')sprers.eu()

The use of the clause is better than adding additional code to the clause because it avoids accidentally catching an exception that wasn’t raised by the code being protected by the … statement.

When an exception occurs, it may have an associated value, also known as the exception’s argument. The presence and type of the argument depend on the exception type.

The except clause may specify a variable after the exception name. The variable is bound to an exception instance with the arguments stored in. For convenience, the exception instance defines so an exception runtime error has occurred arguments can dns error resolving printed directly without having to reference. One may also instantiate an exception first before raising it and add any attributes to it as desired.

>>> try raiseException('spam','eggs') exceptExceptionasinst print(type(inst))# the exception instance print(sprers.eu)# arguments stored in .args print(inst)# __str__ allows args to be printed directly, # but may be overridden in exception subclasses x,y=sprers.eu# unpack args print('x an exception runtime error has occurred print('y =',y)<class 'Exception'>('spam', an exception runtime error has occurred, 'eggs')('spam', 'eggs')x = spamy = eggs

If an exception has arguments, they are printed as the last part (‘detail’) of the message for unhandled exceptions.

Exception handlers don’t just handle exceptions if they occur immediately in the try clause, but also if they occur inside functions that are called (even indirectly) in the try clause. For example:

>>> defthis_fails() x=1/>>> try this_fails() exceptZeroDivisionErroraserr print('Handling run-time error:',err)Handling run-time error: division by zero

Raising Exceptions¶

The statement allows the programmer to force a specified exception to occur. For example:

>>> raiseNameError('HiThere')Traceback (most recent call last): File "<stdin>", an exception runtime error has occurred, line 1, in <module>NameError: HiThere

The sole argument to indicates the exception to be raised. This must be either an exception instance or an exception class (a class that derives from ). If an exception class is passed, it will be implicitly instantiated by calling its constructor with no arguments:

raiseValueError# shorthand for 'raise ValueError()'

If you need to determine whether an exception was raised but don’t intend to handle it, a simpler form of the statement allows you to re-raise the exception:

>>> try raiseNameError('HiThere') exceptNameError print('An exception flew by!') raiseAn exception flew by!Traceback (most recent call last): File "<stdin>", line 2, in <module>NameError: HiThere

Exception Chaining¶

The statement allows an optional which enables chaining exceptions. For example:

# exc must be exception instance or sprers.euuntimeErrorfromexc

This can be useful when you are transforming exceptions. For example:

>>> deffunc() raiseConnectionError>>> try func() exceptConnectionErrorasexc raiseRuntimeError('Failed to open database')fromexcTraceback (most recent call last): File "<stdin>", an exception runtime error has occurred, line 2, in <module> File "<stdin>", line 2, an exception runtime error has occurred funcConnectionErrorThe above exception was the direct cause of the following exception:Traceback (most recent call last): File "<stdin>", an exception runtime error has occurred, line 4, in <module>RuntimeError: Failed to open database

Exception chaining happens automatically when an exception is raised inside an or section. This can be disabled by using idiom:

>>> try open('sprers.eu') exceptOSError raiseRuntimeErrorfromNoneTraceback (most recent call last): File "<stdin>", line 4, in <module>RuntimeError

For more information about chaining mechanics, see Built-in Exceptions.

User-defined Exceptions¶

Programs may name their own exceptions by creating a new exception class (see Classes for more about Python classes). Exceptions istqb fault, error typically be derived from the class, either directly or indirectly.

Exception classes can be defined which do anything any other class can do, but are usually kept simple, often only offering a number of attributes that allow information about the error to be extracted by handlers for the exception.

Most exceptions are defined with names that end in “Error”, similar to the naming of the standard exceptions.

Many standard modules define their own exceptions to report errors that may occur in functions they define. More information on classes is presented in chapter Classes.

Defining Clean-up Actions¶

The statement has another optional clause which is intended to define clean-up actions that must be executed under all circumstances. For example:

>>> try raiseKeyboardInterrupt finally print('Goodbye, world!')Goodbye, an exception runtime error has occurred, world!KeyboardInterruptTraceback (most recent call last): File "<stdin>", line 2, in <module>

If a clause is present, the clause will execute as the last task before the statement completes. The clause runs whether or not the statement produces an exception. The following points discuss more complex cases when an exception occurs:

  • If an exception occurs during execution of the clause, the exception may be handled by an clause. If the exception is not handled by an clause, the exception is re-raised after the clause has been executed.

  • An exception could occur during execution of an or clause. Again, the exception is re-raised after the clause has been executed.

  • If the clause executes aor statement, exceptions are not re-raised.

  • If the statement reaches aor statement, the clause will execute just prior to theor statement’s execution.

  • If a clause includes a statement, the returned value will be the one from the clause’s statement, not the value from the clause’s statement.

For example:

>>> defbool_return() try returnTrue finally returnFalse>>> bool_return()False

A more complicated example:

>>> defdivide(x,y) try result=x/y exceptZeroDivisionError print("division by zero!") else print("result is",result) finally print("executing finally clause")>>> divide(2,1)result is executing finally clause>>> divide(2,0)division by zero!executing finally clause>>> divide("2","1")executing finally clauseTraceback (most recent call last): File "<stdin>", line 1, an exception runtime error has occurred, in <module> File "<stdin>", line 3, in divideTypeError: unsupported operand type(s) for ioerror [errno 13] permission denied 'str' and 'str'

As you can see, the clause is executed in any event. The raised by dividing two strings is not handled by the clause and therefore re-raised after the clause has been executed.

In real world applications, the clause is useful for releasing external resources (such as files or network connections), regardless of whether the use of the resource was successful.

Predefined Clean-up Actions¶

Some objects define standard clean-up actions to be undertaken when the object is no longer needed, regardless of whether or not the operation using the object succeeded or failed. Look at the following example, which tries to open a file and print its contents to the screen.

forlineinopen("sprers.eu"):print(line,end="")

The problem with this code is that it leaves the file open for an indeterminate amount of time after this part of the code has finished executing. This is not an issue in simple scripts, but can be a problem for larger applications, an exception runtime error has occurred. The statement allows objects like files to be used in a way that ensures they are always cleaned up promptly and correctly.

withopen("sprers.eu")asf:forlineinf:print(line,end="")

After the statement is executed, the file f is always closed, even if a problem was encountered while processing the lines. Objects which, like files, provide predefined clean-up actions will indicate this in their documentation.

Issue

 

You saw an error message similar to the following:

OpenDCL Runtime Error: An OpenDCL function argument processing exception has occurred!

Error NIL value not allowed

Function: dcl_Form_show

Argument: 0

OpenDCL Runtime Error

 

 

You may have also received a message that The helper library is out of date.

 

 

Cause

Your OpenDCL library is not loaded correctly, which is preventing you from accessing content from the Land F/X database.

 

Solution

First, try restarting CAD. In most cases, this will resolve the issue.

 

If, after restarting CAD, you are still receiving an OpenDCL error message, your next step should be to install the latest version of OpenDCL.

 

Restart CAD once again. You should now be able to perform the action that generated the error message.

Errors and exceptions

Answers to exercises¶

Answer to exercise 1¶

  1. There are five syntax errors:

    1. Missing keyword in function definition
    2. clause without an
    3. Missing colon after condition
    4. Spelling mistake (&#;esle&#;)
    5. The block is empty because the statement is not indented correctly
    1. The values entered by the user may not be valid integers or floating point numbers.
    2. The user may enter zero for the divisor.
    3. If the library hasn&#;t been imported, is undefined.
    1. , and need to be defined before this snippet.
    2. The attempt to access the list element with index may fail during one of the loop iterations if the range from to exceeds the size of .
    3. The string formatting operation inside the statement expects to be a tuple with three numbers. If it has too many or too few elements, or isn&#;t a tuple at all, the attempt to format the string will epson gs6000 error 1136 you are accumulating a number total by multiplication, not addition, you need to initialise the total tonototherwise the product will always be zero!
    4. The line which adds to is not aligned correctly, and will only add the last value of after the loop has concluded.
    5. The wrong variable is used: an exception runtime error has occurred each loop iteration the current number in the range is added to itself and remains unchanged.

Answer to exercise 2¶

  1. Here is an example program:

    person={}properties=[("name",str),("surname",str),("age",int),("height",float),("weight",float),]forproperty,p_typeinproperties:valid_value=Nonewhilevalid_valueisNone:try:value=input("Please enter your %s: "%property)valid_value=p_type(value)exceptValueError:print("Could not convert %s '%s' to type %s. Please try again."%(property,value,p_type.__name__))person[property]=valid_value
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexError:print("The list has no element at index %d."%index)
  3. Here is an example program:

    defadd_to_list_in_dict(thedict,listname,element):try:l=thedict[listname]exceptKeyError:thedict[listname]=[]print("Created %s."%listname)else:print("%s already has %d elements."%(listname,len(l)))finally:thedict[listname].append(element)print("Added %s to %s."%(element,listname))

Answer to exercise 3¶

  1. Here is an example program:

    person={}properties=[("name",str),("surname",str),("age",int),("height",float),("weight",float),]forproperty,p_typeinproperties:valid_value=Nonewhilevalid_valueisNone:try:value=input("Please enter your %s: "%property)valid_value=p_type(value)exceptValueErrorasve:print(ve)person[property]=valid_value
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexErrorasie:print("The list has no element at index %d."%index)raiseie

Answer to exercise 4¶

  1. Here is an example of the logging configuration:

    sprers.euonfig(filename='sprers.eu',level=sprers.eu)
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexError:sprers.eu("The list has no element at index %d."%index)
  3. Here is an example program:

    defadd_to_list_in_dict(thedict,listname,element):try:l=thedict[listname]exceptKeyError:thedict[listname]=[]sprers.eu("Created %s."%listname)else:sprers.eu("%s already has %d elements."%(listname,len(l)))finally:thedict[listname].append(element)sprers.eu("Added %s to %s."%(element,listname))
Answer

Hi L.D,

A.      When exactly do you get the run time error?

B.      From when are you getting this error?

You may try this step as a workaround.

1.       Open internet explorer >> Tools >> internet options

2.       Click on the Advanced tab

3.       Scroll down to browsing and check the box for “Disable script debugging “

4.       Uncheck the box for "Display a notification about every script error"

5.       Click "Apply", "OK"

6.       Check the status.

You may also refer the article given below.
sprers.eu

Hope this helps.

Bindu S- Microsoft Support

[If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]

Report abuse

Harassment is any behavior intended to disturb or upset a person or group of people. Threats include any threat of suicide, violence, or harm to another. Any content of an adult theme or inappropriate to a community web site. Any image, link, or discussion of nudity. Any behavior that is insulting, rude, vulgar, desecrating, or showing disrespect. Any behavior that an exception runtime error has occurred to violate End user license agreements, including providing product keys or links to pirated software. Unsolicited bulk mail or bulk advertising. Any link to or advocacy of virus, spyware, malware, or phishing sites. Any other inappropriate content or behavior as defined by the Terms of Use or An exception runtime error has occurred of Conduct. Any image, link, or discussion related to child pornography, child nudity, or other child abuse or exploitation.
Details (required):
characters remaining

3 people found this reply helpful

·

Was this reply helpful?

Sorry this didn't help.

Great! Thanks for your feedback.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this reply?

Thanks for your feedback.

Can you give more detail about what you mean with "the old way" and the "new way" ?


This issue an exception runtime error has occurred be caused by corrupted cookies, an exception runtime error has occurred.

  • check the permissions for the domain in the currently selected tab in "Tools -> Page Info -> Permissions"

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" for websites that cause problems:

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data: "Manage Data"

"Clear the Cache":

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Can you give more detail about what you mean with "the old way" and the "new way" ? This issue can be caused by corrupted cookies. *check the permissions for the domain in the currently selected tab in "Tools -> Page Info -> Permissions" Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences). "Remove the Cookies" for websites that cause problems: *Options/Preferences -> Privacy & Security<br>Cookies and Site Data: "Manage Data" "Clear the Cache": *Options/Preferences -> Privacy & Security<br>Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

an exception runtime error has occurred

An exception runtime error has occurred - happens

How to Solve the Most Common Runtime Errors in Java

A runtime error in Java is an application error that occurs during the execution of a program. A runtime error occurs when a program is syntactically correct but contains an issue that is only detected during program execution. These issues cannot be caught at compile-time by the Java compiler and are only detected by the Java Virtual Machine (JVM) when the application is running.

Runtime errors are a category of exception that contains several more specific error types. Some of the most common types of runtime errors are:

  • IO errors
  • Division by zero errors
  • Out of range errors
  • Undefined object errors

Runtime Errors vs Compile-Time Errors

Compile-time errors occur when there are syntactical issues present in application code, for example, missing semicolons or parentheses, misspelled keywords or usage of undeclared variables.

These syntax errors are detected by the Java compiler at compile-time and an error message is displayed on the screen. The compiler prevents the code from being executed until the error is fixed. Therefore, these errors must be addressed by debugging before the program can be successfully run.

On the other hand, runtime errors occur during program execution (the interpretation phase), after compilation has taken place. Any code that throws a runtime error is therefore syntactically correct.

Runtime Errors vs Logical Errors

A runtime error could potentially be a legitimate issue in code, for example, incorrectly formatted input data or lack of resources (e.g. insufficient memory or disk space). When a runtime error occurs in Java, the compiler specifies the lines of code where the error is encountered. This information can be used to trace back where the problem originated.

On the other hand, a logical error is always the symptom of a bug in application code leading to incorrect output e.g. subtracting two variables instead of adding them. In case of a logical error, the program operates incorrectly but does not terminate abnormally. Each statement may need to be checked to identify a logical error, which makes it generally harder to debug than a runtime error.

What Causes Runtime Errors in Java

The most common causes of runtime errors in Java are:

  • Dividing a number by zero.
  • Accessing an element in an array that is out of range.
  • Attempting to store an incompatible type value to a collection.
  • Passing an invalid argument to a method.
  • Attempting to convert an invalid string to a number.
  • Insufficient space in memory for thread data.

When any such errors are encountered, the Java compiler generates an error message and terminates the program abnormally. Runtime errors don’t need to be explicitly caught and handled in code. However, it may be useful to catch them and continue program execution.

To handle a runtime error, the code can be placed within a try-catch block and the error can be caught inside the catch block.

Runtime Error Examples

Division by zero error

Here is an example of a , a type of runtime exception, thrown due to division by zero:

In this example, an integer is attempted to be divided by another integer , whose value is zero, leading to a :

Accessing an out of range value in an array

Here is an example of a thrown due to an attempt to access an element in an array that is out of bounds:

In this example, an array is initialized with 5 elements. An element at position 5 is later attempted to be accessed in the array, which does not exist, leading to a runtime error:

How to Solve Runtime Errors

Runtime errors can be handled in Java using try-catch blocks with the following steps:

  • Surround the statements that can throw a runtime error in try-catch blocks.
  • Catch the error.
  • Depending on the requirements of the application, take necessary action. For example, log the exception with an appropriate message.

To illustrate this, the code in the earlier example can be updated with the above steps:

Surrounding the code in try-catch blocks like the above allows the program to continue execution after the exception is encountered:

Runtime errors can be avoided where possible by paying attention to detail and making sure all statements in code are mathematically and logically correct.

Track, Analyze and Manage Errors With Rollbar

![Rollbar in action]([email protected])

Managing errors and exceptions in your code is challenging. It can make deploying production code an unnerving experience. Being able to track, analyze, and manage errors in real-time can help you to proceed with more confidence. Rollbar automates error monitoring and triaging, making fixing errors easier than ever. Try it today.

Can you give more detail about what you mean with "the old way" and the "new way" ?


This issue can be caused by corrupted cookies.

  • check the permissions for the domain in the currently selected tab in "Tools -> Page Info -> Permissions"

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" for websites that cause problems:

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data: "Manage Data"

"Clear the Cache":

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Can you give more detail about what you mean with "the old way" and the "new way" ? This issue can be caused by corrupted cookies. *check the permissions for the domain in the currently selected tab in "Tools -> Page Info -> Permissions" Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences). "Remove the Cookies" for websites that cause problems: *Options/Preferences -> Privacy & Security<br>Cookies and Site Data: "Manage Data" "Clear the Cache": *Options/Preferences -> Privacy & Security<br>Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Troubleshooting

Even the most experienced developer rarely writes code correctly on the first try, making troubleshooting an important part of the development process. In this section we'll cover some techniques that can help you find, understand, and debug errors in your scripts.

Error messages

When your script encounters an error, an error message is displayed. The message is accompanied by a line number used for troubleshooting. There are two basic types of errors displayed in this way: syntax errors and runtime errors.

Syntax errors

Syntax errors are caused by writing code that doesn't follow the JavaScript grammar, and the errors are detected as soon as you try to save the script. For example, the following code snippet contains a syntax error:

The syntax problem here is a missing character at the end of the fourth line. When you try to save the script you'll get the following error:

Missing ) after argument list. (line 4)

These types of errors are usually simple to troubleshoot, since they are found right away and typically have simple causes. You aren't able to save a file that contains syntax errors, meaning that only valid code is saved into your project.

Runtime errors

These errors are caused by using a function or class incorrectly, and can only be detected once the script has been run. For example, the following code causes a runtime error:

The code is formatted correctly, but we are passing the value "john" for the email address when calling . Since this is not a valid email address the following error is thrown when running the script:

Invalid email: john (line 5)

What makes these errors more challenging to troubleshoot is that often the data you are passing into a function is not written in the code, but instead pulled from a spreadsheet, form, or other external data source. Using the debugging techniques below can help you to identify the cause of these errors.

Common errors

Below is a list of common errors and their causes.

Service invoked too many times: <action name>

This error indicates that you have exceeded your daily quota for a given action. For example, you might encounter this error if you send too many emails in a single day. The quotas are set at different levels for consumer, domain, and premier accounts and are subject to change at any time without a prior announcement by Google. You can view the quota limits for various actions in the Apps Script quota documentation.

Server not available. or Server error occurred, please try again.

There are a few possible causes for these errors:

  • A Google server or system is temporarily unavailable. Wait for a few moments and try running the script again.
  • There is an error in your script that doesn't have a corresponding error message. Try debugging your script and see if you can isolate the problem.
  • There is a bug in Google Apps Script that is causing this error. For instructions on searching for and filing bug reports, see the Bugs. Before filing a new bug, search to see if others have already reported it.

Authorization is required to perform that action.

This error indicates that the script is lacking the authorization needed to run. When a script is run in the Script Editor or from a custom menu item an authorization dialog is presented to the user. However, when a script is run from a trigger, embedded with a Google Sites page, or run as a service, the dialog cannot be presented and this error is shown.

To authorize the script, open the Script Editor and run any function. The authorization prompt appears so you can authorize the script project. If the script contains new unauthorized services, you must re-authorize the script.

This error is frequently caused by triggers that are firing before the user has authorized them. If you don't have access to the script project (because the error is occurring for an add-on you use, for example), you can usually authorize the script by using the add-on again. If a trigger continues to fire and cause this error, you can remove your triggers by doing the following:

New editor

  1. At the left of the Apps Script project, click Triggersalarm.
  2. At the right of the trigger you want to remove, click More more_vert> Delete trigger.

Legacy editor

  1. Select Edit > All your triggers in the Apps Script editor. The resulting dialog shows all active triggers running on your account.
  2. Find the offending trigger in the list.
  3. Click the clear icon next to the trigger name to remove it.
  4. Click Save to record the deletion.

You can also remove problematic add-on triggers by uninstalling the add-on.

Access denied: DriveApp or The domain policy has disabled third-party Drive apps

Administrators of Google Workspace domains have the ability to disable the Drive SDK for their domain, which prevents their users from installing and using Google Drive apps. This setting also prevents the users from being able to use Apps Script add-ons that use the Drive service or Advanced Drive Service (even if the script was authorized prior to the admin disabling Drive SDK).

However, if an add-on or web app using the Drive service is published for domain-wide installation and is installed by the administrator for some or all users in the domain, the script functions for those users even if the Drive SDK is disabled in the domain.

The script does not have permission to get the active user's identity.

Indicates that the active user's identity and email are not available to the script. This warning results from a call to . It can also result from a call to if the script is running in an authorization mode other than . If this warning is signaled, subsequent calls to only return "".

There are a number of ways to troubleshoot this warning, depending on the authorization mode the script is running under. The authorization mode is exposed in triggered functions as the property of the event parameter.

Library is missing

If you add a popular library to your script, you might receive an error message stating that it's missing, even though the library is listed as a dependency for your script. The reason might be that too many people are accessing the library at the same time. To avoid this error, try one of the following solutions:

  • Copy and paste the library's code into your script and remove the library dependency.
  • Copy the library script and deploy it as a library from your account. Be sure to update the dependency in your original script to the new library instead of the public one.

Debugging

Not all mistakes cause an error message to be displayed. There might be a more subtle error where the code is technically correct and can execute, but the results are not what you expect. Here are some strategies for handling such situations and further investigating a script that is not running the way you expect.

Logging

While debugging it's often helpful to record information as a script project executes. Google Apps Script has two methods for logging information: the Cloud logging service and the more basic Logger and console services that are built in to the Apps Script editor.

See the Logging guide for more details.

Error Reporting

Note: To use Error Reporting in Google Cloud Platform, your Apps Script project must use a standard, user-managed GCP project instead of the default, Apps Script-managed GCP project.

Exceptions that occur because of runtime errors are automatically recorded using the Google Cloud Error Reporting service. This service lets you search and filter exception messages your script project creates.

New editor

To access Error Reporting, see View Cloud logs and error reports in the Google Cloud Platform console.

Legacy editor

You can enable Error Reporting the first time you select View > Stackdriver Logging or View > Stackdriver Error Reporting in a new script.

Once enabled, exceptions that occur because of runtime errors are automatically recorded using the Google Cloud Stackdriver service. This service lets you search and filter exception messages your script project creates. You can reach the Stackdriver Error Reporting interface by selecting View > Stackdriver Error Reporting in the Apps Script editor.

Executions

New editor

Every time you run a script, Apps Script makes a record of the execution, including the Cloud logs. These records can help you understand which actions your script performed.

To view the executions of your script in the Apps Script project, at the left, click Executionsplaylist_play.

Legacy editor

Every time you run a script, Apps Script makes a record of the execution, including the Cloud logs. These records can help you to understand which actions your script performed. To view the executions of your script, select View > Executions in the Apps Script editor. This opens the Executions panel for the script in the Apps Script dashboard.

Checking Apps Script service status

Although rare, sometimes specific Google Workspace services (such as Gmail or Drive) encounter temporary problems that can lead to service outages. When this occurs, Apps Script projects that interact with these services may not function as expected.

You can check if there is a Google Workspace service outage by viewing the Google Workspace Status Dashboard. If an outage is currently being experienced, you either wait for it to be resolved or seek additional help in the Google Workspace Help Center or the Google Workspace Known Issues documentation.

Use the debugger and breakpoints

To locate problems in your script, you can run it in debug mode. When run in debug mode, a script pauses when it hits a breakpoint, which is a line you've highlighted in your script that you think may have a problem. When a script pauses it displays the value of each variable at that point in time, allowing you to inspect the inner workings of a script without having to add a lot of logging statements.

Add a breakpoint

New editor

To add a breakpoint, hover over the line number of the line you want to add the breakpoint to. At the left of the line number, click the circle. The below image shows an example of a breakpoint added to a script:

Add a breakpoint

Legacy editor

To add a breakpoint click on the line number for the line you want to pause at.

Run a script in debug mode

New editor

To run the script in debug mode, at the top of the editor click Debug.

Before the script runs the line with the breakpoint it pauses and displays a table of debug information. You can use this table to inspect data like the values of parameters and the information stored in objects.

To control how the script is run, at the top of the Debugger panel, use the "Step in", "Step over", and "Step out" buttons. These let you run the script one line at a time and inspect how values change over time.

Legacy editor

To run the script in debug mode, click the bug icon (Bug icon) in the toolbar. Before the script runs the line with the breakpoint it pauses and displays a table of debug information.

This table allows you to inspect the values of the parameters like and , as well as the information stored in the object. Notice that the variable doesn't have a value assigned yet, because the script paused before that line was executed.

When the script is paused, an extra set of buttons are displayed in the toolbar which allow you to control how the script is run. Using the "step in", "step over", and "step out" buttons you can run the script one line at a time, allowing you to inspect how values change over time.

Issues with multiple Google Accounts

If you're logged into multiple Google Accounts at the same time, you might have trouble accessing your Apps Script projects, add-ons, and web apps. Multi-login, or being logged into multiple Google Accounts at once, isn't supported for Apps Script, add-ons, or web apps.

To fix issues from multi-login, try one of the following solutions:

  • Log out of all your Google Accounts and only log in to the one that has the Apps Script project, add-on, or web app you need to access.
  • Open an incognito window in Google Chrome, or an equivalent private browsing window, and log in to the Google Account that has the Apps Script project, add-on, or web app you need to access.

Getting help

Debugging a problem using the tools and techniques listed above can solve a variety of problems, but there may be issues you run into that require some extra help to solve. See our Support page for information on where to ask questions and file bugs.

8. Errors and Exceptions¶

Until now error messages haven’t been more than mentioned, but if you have tried out the examples you have probably seen some. There are (at least) two distinguishable kinds of errors: syntax errors and exceptions.

Syntax Errors¶

Syntax errors, also known as parsing errors, are perhaps the most common kind of complaint you get while you are still learning Python:

>>> whileTrueprint('Hello world') File "<stdin>", line 1whileTrueprint('Hello world')^SyntaxError: invalid syntax

The parser repeats the offending line and displays a little ‘arrow’ pointing at the earliest point in the line where the error was detected. The error is caused by (or at least detected at) the token preceding the arrow: in the example, the error is detected at the function , since a colon () is missing before it. File name and line number are printed so you know where to look in case the input came from a script.

Exceptions¶

Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Errors detected during execution are called exceptions and are not unconditionally fatal: you will soon learn how to handle them in Python programs. Most exceptions are not handled by programs, however, and result in error messages as shown here:

>>> 10*(1/0)Traceback (most recent call last): File "<stdin>", line 1, in <module>ZeroDivisionError: division by zero>>> 4+spam*3Traceback (most recent call last): File "<stdin>", line 1, in <module>NameError: name 'spam' is not defined>>> '2'+2Traceback (most recent call last): File "<stdin>", line 1, in <module>TypeError: can only concatenate str (not "int") to str

The last line of the error message indicates what happened. Exceptions come in different types, and the type is printed as part of the message: the types in the example are , and . The string printed as the exception type is the name of the built-in exception that occurred. This is true for all built-in exceptions, but need not be true for user-defined exceptions (although it is a useful convention). Standard exception names are built-in identifiers (not reserved keywords).

The rest of the line provides detail based on the type of exception and what caused it.

The preceding part of the error message shows the context where the exception occurred, in the form of a stack traceback. In general it contains a stack traceback listing source lines; however, it will not display lines read from standard input.

Built-in Exceptions lists the built-in exceptions and their meanings.

Handling Exceptions¶

It is possible to write programs that handle selected exceptions. Look at the following example, which asks the user for input until a valid integer has been entered, but allows the user to interrupt the program (using or whatever the operating system supports); note that a user-generated interruption is signalled by raising the exception.

>>> whileTrue try x=int(input("Please enter a number: ")) break exceptValueError print("Oops! That was no valid number. Try again")

The statement works as follows.

  • First, the try clause (the statement(s) between the and keywords) is executed.

  • If no exception occurs, the except clause is skipped and execution of the statement is finished.

  • If an exception occurs during execution of the clause, the rest of the clause is skipped. Then, if its type matches the exception named after the keyword, the except clause is executed, and then execution continues after the try/except block.

  • If an exception occurs which does not match the exception named in the except clause, it is passed on to outer statements; if no handler is found, it is an unhandled exception and execution stops with a message as shown above.

A statement may have more than one except clause, to specify handlers for different exceptions. At most one handler will be executed. Handlers only handle exceptions that occur in the corresponding try clause, not in other handlers of the same statement. An except clause may name multiple exceptions as a parenthesized tuple, for example:

except(RuntimeError,TypeError,NameError)pass

A class in an clause is compatible with an exception if it is the same class or a base class thereof (but not the other way around — an except clause listing a derived class is not compatible with a base class). For example, the following code will print B, C, D in that order:

classB(Exception):passclassC(B):passclassD(C):passforclsin[B,C,D]:try:raisecls()exceptD:print("D")exceptC:print("C")exceptB:print("B")

Note that if the except clauses were reversed (with first), it would have printed B, B, B — the first matching except clause is triggered.

All exceptions inherit from , and so it can be used to serve as a wildcard. Use this with extreme caution, since it is easy to mask a real programming error in this way! It can also be used to print an error message and then re-raise the exception (allowing a caller to handle the exception as well):

importsystry:f=open('sprers.eu')s=sprers.eune()i=int(sprers.eu())exceptOSErroraserr:print("OS error: {0}".format(err))exceptValueError:print("Could not convert data to an integer.")exceptBaseExceptionaserr:print(f"Unexpected {err=}, {type(err)=}")raise

Alternatively the last except clause may omit the exception name(s), however the exception value must then be retrieved from .

The … statement has an optional else clause, which, when present, must follow all except clauses. It is useful for code that must be executed if the try clause does not raise an exception. For example:

sprers.eu[1:]:try:f=open(arg,'r')exceptOSError:print('cannot open',arg)else:print(arg,'has',len(sprers.eunes()),'lines')sprers.eu()

The use of the clause is better than adding additional code to the clause because it avoids accidentally catching an exception that wasn’t raised by the code being protected by the … statement.

When an exception occurs, it may have an associated value, also known as the exception’s argument. The presence and type of the argument depend on the exception type.

The except clause may specify a variable after the exception name. The variable is bound to an exception instance with the arguments stored in . For convenience, the exception instance defines so the arguments can be printed directly without having to reference . One may also instantiate an exception first before raising it and add any attributes to it as desired.

>>> try raiseException('spam','eggs') exceptExceptionasinst print(type(inst))# the exception instance print(sprers.eu)# arguments stored in .args print(inst)# __str__ allows args to be printed directly, # but may be overridden in exception subclasses x,y=sprers.eu# unpack args print('x =',x) print('y =',y)<class 'Exception'>('spam', 'eggs')('spam', 'eggs')x = spamy = eggs

If an exception has arguments, they are printed as the last part (‘detail’) of the message for unhandled exceptions.

Exception handlers don’t just handle exceptions if they occur immediately in the try clause, but also if they occur inside functions that are called (even indirectly) in the try clause. For example:

>>> defthis_fails() x=1/>>> try this_fails() exceptZeroDivisionErroraserr print('Handling run-time error:',err)Handling run-time error: division by zero

Raising Exceptions¶

The statement allows the programmer to force a specified exception to occur. For example:

>>> raiseNameError('HiThere')Traceback (most recent call last): File "<stdin>", line 1, in <module>NameError: HiThere

The sole argument to indicates the exception to be raised. This must be either an exception instance or an exception class (a class that derives from ). If an exception class is passed, it will be implicitly instantiated by calling its constructor with no arguments:

raiseValueError# shorthand for 'raise ValueError()'

If you need to determine whether an exception was raised but don’t intend to handle it, a simpler form of the statement allows you to re-raise the exception:

>>> try raiseNameError('HiThere') exceptNameError print('An exception flew by!') raiseAn exception flew by!Traceback (most recent call last): File "<stdin>", line 2, in <module>NameError: HiThere

Exception Chaining¶

The statement allows an optional which enables chaining exceptions. For example:

# exc must be exception instance or sprers.euuntimeErrorfromexc

This can be useful when you are transforming exceptions. For example:

>>> deffunc() raiseConnectionError>>> try func() exceptConnectionErrorasexc raiseRuntimeError('Failed to open database')fromexcTraceback (most recent call last): File "<stdin>", line 2, in <module> File "<stdin>", line 2, in funcConnectionErrorThe above exception was the direct cause of the following exception:Traceback (most recent call last): File "<stdin>", line 4, in <module>RuntimeError: Failed to open database

Exception chaining happens automatically when an exception is raised inside an or section. This can be disabled by using idiom:

>>> try open('sprers.eu') exceptOSError raiseRuntimeErrorfromNoneTraceback (most recent call last): File "<stdin>", line 4, in <module>RuntimeError

For more information about chaining mechanics, see Built-in Exceptions.

User-defined Exceptions¶

Programs may name their own exceptions by creating a new exception class (see Classes for more about Python classes). Exceptions should typically be derived from the class, either directly or indirectly.

Exception classes can be defined which do anything any other class can do, but are usually kept simple, often only offering a number of attributes that allow information about the error to be extracted by handlers for the exception.

Most exceptions are defined with names that end in “Error”, similar to the naming of the standard exceptions.

Many standard modules define their own exceptions to report errors that may occur in functions they define. More information on classes is presented in chapter Classes.

Defining Clean-up Actions¶

The statement has another optional clause which is intended to define clean-up actions that must be executed under all circumstances. For example:

>>> try raiseKeyboardInterrupt finally print('Goodbye, world!')Goodbye, world!KeyboardInterruptTraceback (most recent call last): File "<stdin>", line 2, in <module>

If a clause is present, the clause will execute as the last task before the statement completes. The clause runs whether or not the statement produces an exception. The following points discuss more complex cases when an exception occurs:

  • If an exception occurs during execution of the clause, the exception may be handled by an clause. If the exception is not handled by an clause, the exception is re-raised after the clause has been executed.

  • An exception could occur during execution of an or clause. Again, the exception is re-raised after the clause has been executed.

  • If the clause executes a , or statement, exceptions are not re-raised.

  • If the statement reaches a , or statement, the clause will execute just prior to the , or statement’s execution.

  • If a clause includes a statement, the returned value will be the one from the clause’s statement, not the value from the clause’s statement.

For example:

>>> defbool_return() try returnTrue finally returnFalse>>> bool_return()False

A more complicated example:

>>> defdivide(x,y) try result=x/y exceptZeroDivisionError print("division by zero!") else print("result is",result) finally print("executing finally clause")>>> divide(2,1)result is executing finally clause>>> divide(2,0)division by zero!executing finally clause>>> divide("2","1")executing finally clauseTraceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 3, in divideTypeError: unsupported operand type(s) for /: 'str' and 'str'

As you can see, the clause is executed in any event. The raised by dividing two strings is not handled by the clause and therefore re-raised after the clause has been executed.

In real world applications, the clause is useful for releasing external resources (such as files or network connections), regardless of whether the use of the resource was successful.

Predefined Clean-up Actions¶

Some objects define standard clean-up actions to be undertaken when the object is no longer needed, regardless of whether or not the operation using the object succeeded or failed. Look at the following example, which tries to open a file and print its contents to the screen.

forlineinopen("sprers.eu"):print(line,end="")

The problem with this code is that it leaves the file open for an indeterminate amount of time after this part of the code has finished executing. This is not an issue in simple scripts, but can be a problem for larger applications. The statement allows objects like files to be used in a way that ensures they are always cleaned up promptly and correctly.

withopen("sprers.eu")asf:forlineinf:print(line,end="")

After the statement is executed, the file f is always closed, even if a problem was encountered while processing the lines. Objects which, like files, provide predefined clean-up actions will indicate this in their documentation.

Errors and exceptions

Answers to exercises¶

Answer to exercise 1¶

  1. There are five syntax errors:

    1. Missing keyword in function definition
    2. clause without an
    3. Missing colon after condition
    4. Spelling mistake (&#;esle&#;)
    5. The block is empty because the statement is not indented correctly
    1. The values entered by the user may not be valid integers or floating point numbers.
    2. The user may enter zero for the divisor.
    3. If the library hasn&#;t been imported, is undefined.
    1. , and need to be defined before this snippet.
    2. The attempt to access the list element with index may fail during one of the loop iterations if the range from to exceeds the size of .
    3. The string formatting operation inside the statement expects to be a tuple with three numbers. If it has too many or too few elements, or isn&#;t a tuple at all, the attempt to format the string will fail.
    1. If you are accumulating a number total by multiplication, not addition, you need to initialise the total to , not , otherwise the product will always be zero!
    2. The line which adds to is not aligned correctly, and will only add the last value of after the loop has concluded.
    3. The wrong variable is used: at each loop iteration the current number in the range is added to itself and remains unchanged.

Answer to exercise 2¶

  1. Here is an example program:

    person={}properties=[("name",str),("surname",str),("age",int),("height",float),("weight",float),]forproperty,p_typeinproperties:valid_value=Nonewhilevalid_valueisNone:try:value=input("Please enter your %s: "%property)valid_value=p_type(value)exceptValueError:print("Could not convert %s '%s' to type %s. Please try again."%(property,value,p_type.__name__))person[property]=valid_value
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexError:print("The list has no element at index %d."%index)
  3. Here is an example program:

    defadd_to_list_in_dict(thedict,listname,element):try:l=thedict[listname]exceptKeyError:thedict[listname]=[]print("Created %s."%listname)else:print("%s already has %d elements."%(listname,len(l)))finally:thedict[listname].append(element)print("Added %s to %s."%(element,listname))

Answer to exercise 3¶

  1. Here is an example program:

    person={}properties=[("name",str),("surname",str),("age",int),("height",float),("weight",float),]forproperty,p_typeinproperties:valid_value=Nonewhilevalid_valueisNone:try:value=input("Please enter your %s: "%property)valid_value=p_type(value)exceptValueErrorasve:print(ve)person[property]=valid_value
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexErrorasie:print("The list has no element at index %d."%index)raiseie

Answer to exercise 4¶

  1. Here is an example of the logging configuration:

    sprers.euonfig(filename='sprers.eu',level=sprers.eu)
  2. Here is an example program:

    defprint_list_element(thelist,index):try:print(thelist[index])exceptIndexError:sprers.eu("The list has no element at index %d."%index)
  3. Here is an example program:

    defadd_to_list_in_dict(thedict,listname,element):try:l=thedict[listname]exceptKeyError:thedict[listname]=[]sprers.eu("Created %s."%listname)else:sprers.eu("%s already has %d elements."%(listname,len(l)))finally:thedict[listname].append(element)sprers.eu("Added %s to %s."%(element,listname))

1 Comments

Leave a Comment