[pytest-dev] [3.1 feature] "assert not raise exception" helper: opinions about the name

[Ronny Pfannschmidt]

i meant the except clause

In [1]: try:
   ...:     1/0
   ...: except None:
   ...:     pass
   ...:
---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-1-0d5ef3af74e6> in <module>()
      1 try:
----> 2     1/0
      3 except None:
      4     pass

ZeroDivisionError: integer division or modulo by zero


vs


In [1]: try:
   ...:     1/0
   ...: except None:
   ...:     pass
   ...:
---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-1-0d5ef3af74e6> in <module>()
      1 try:
----> 2     1/0
      3 except None:

ZeroDivisionError: division by zero

During handling of the above exception, another exception occurred:

TypeError                                 Traceback (most recent call last)
<ipython-input-1-0d5ef3af74e6> in <module>()
      1 try:
      2     1/0
----> 3 except None:
      4     pass

TypeError: catching classes that do not inherit from BaseException is
not allowed


On 05.04.2017 17:46, Florian Bruhin wrote:
> Hey,
>
> On Wed, Apr 05, 2017 at 05:25:01PM +0200, Ronny Pfannschmidt wrote:
>> while experimenting i learned of the fun fact that None is a "valid
>> exception type"
>> for except clauses on at least python 2.7
> But it doesn't seem to be possible to raise it:
>
>     Python 2.7.13 (default, Dec 21 2016, 07:16:46)
>     >>> raise None
>     Traceback (most recent call last):
>       File "<stdin>", line 1, in <module>
>     TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType
>
> Florian
>