3.6 Standard Module traceback

 

This module provides a standard interface to format and print stack traces of Python programs. It exactly mimics the behavior of the Python interpreter when it prints a stack trace. This is useful when you want to print stack traces under program control, e.g. in a ``wrapper'' around the interpreter.

The module uses traceback objects -- this is the object type that is stored in the variables sys.exc_traceback and sys.last_traceback.  

The module defines the following functions:

print_tb (traceback[, limit])

Print up to limit stack trace entries from traceback. If limit is omitted or None, all entries are printed.

extract_tb (traceback[, limit])

Return a list of up to limit ``pre-processed'' stack trace entries extracted from traceback. It is useful for alternate formatting of stack traces. If limit is omitted or None, all entries are extracted. A ``pre-processed'' stack trace entry is a quadruple (filename, line number, function name, line text) representing the information that is usually printed for a stack trace. The line text is a string with leading and trailing whitespace stripped; if the source is not available it is None.

print_exception (type, value, traceback[, limit])

Print exception information and up to limit stack trace entries from traceback. This differs from print_tb() in the following ways: (1) if traceback is not None, it prints a header "Traceback (innermost last):"; (2) it prints the exception type and value after the stack trace; (3) if type is SyntaxError and value has the appropriate format, it prints the line where the syntax error occurred with a caret indicating the approximate position of the error.

print_exc ([limit])

This is a shorthand for `print_exception(sys.exc_type, sys.exc_value, sys.exc_traceback, limit)'.

print_last ([limit])

This is a shorthand for `print_exception(sys.last_type, sys.last_value, sys.last_traceback, limit)'.