#!# ============
#!#  Exceptions
#!# ============
#!#
#!# This page contains a memo on exceptions.
#!#
#!# For a complete reference documentation, look at https://docs.python.org/3/reference/compound_stmts.html#try

from Tools import *

#!#
#!# Catch exceptions using :code:`try` block:

try:
    x = 1 / 0
except ZeroDivisionError as exception:
    pretty_print((exception, exception.__traceback__))
except ZeroDivisionError:
    # If we don't need the exception instance
    print('try block failed')
except Exception as exception:
    # Catch all exceptions
    print(exception)
except:
    # Shorter form to catch all exceptions
    pass # simply ignore the exception
#o#

#!#
#!# Use :code:`finally` to do cleanup:

try:
    x = 1 / 1
except Exception as exception:
    print(exception)
finally:
    print('try block succeed')
#o#

#!#
#!# Raise exceptions:

try:
    raise NameError("Something bad happened")
except Exception as exception:
    print(exception)
#o#

try:
    try:
        1 / 0
    except ZeroDivisionError:
        raise # last exception
except Exception as exception:
    print(exception)
#o#

#!#
#!# Chain exceptions:

try:
    try:
        1 / 0
    except ZeroDivisionError as exception:
        raise NameError("Something bad happened") from exception
except Exception as exception:
    print(exception, ', caused by:', exception.__cause__)
#o#

#!# **To be completed:** :code:`exception.__context__`

3.3.7. Exceptions¶

This page contains a memo on exceptions.

For a complete reference documentation, look at https://docs.python.org/3/reference/compound_stmts.html#try

from Tools import *

Catch exceptions using try block:

try:
    x = 1 / 0
except ZeroDivisionError as exception:
    pretty_print((exception, exception.__traceback__))
except ZeroDivisionError:
    # If we don't need the exception instance
    print('try block failed')
except Exception as exception:
    # Catch all exceptions
    print(exception)
except:
    # Shorter form to catch all exceptions
    pass # simply ignore the exception

(   ZeroDivisionError('division by zero',),
    <traceback object at 0x7f090cc5cf08>)

Use finally to do cleanup:

try:
    x = 1 / 1
except Exception as exception:
    print(exception)
finally:
    print('try block succeed')

try block succeed

Raise exceptions:

try:
    raise NameError("Something bad happened")
except Exception as exception:
    print(exception)

Something bad happened

try:
    try:
        1 / 0
    except ZeroDivisionError:
        raise # last exception
except Exception as exception:
    print(exception)

division by zero

Chain exceptions:

try:
    try:
        1 / 0
    except ZeroDivisionError as exception:
        raise NameError("Something bad happened") from exception
except Exception as exception:
    print(exception, ', caused by:', exception.__cause__)

Something bad happened , caused by: division by zero

To be completed: exception.__context__