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Count warnings in Python 2.4

I've got some tests that need to count the number of warnings raised by a function. In Python 2.6 this is simple, using

with warnings.catch_warnings(record=True) as warn:
    self.assertEquals(len(warn), 2)

Unfortunately, with is not available in Python 2.4, so what else could I use? I can't simply check if there's been a single warning (using warning filter with action='error' and try/catch), because the number of warnings is significant.

like image 288
l0b0 Avatar asked Feb 24 '10 09:02


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1 Answers

I was going to suggest the same workaround as Ignacio, a bit more complete example of testing code:

import warnings

def setup_warning_catcher():
    """ Wrap warnings.showwarning with code that records warnings. """

    caught_warnings = []
    original_showwarning = warnings.showwarning

    def custom_showwarning(*args,  **kwargs):
        return original_showwarning(*args, **kwargs)

    warnings.showwarning = custom_showwarning
    return caught_warnings

caught_warnings_list = setup_warning_catcher()

# trigger warning here

assert len(caught_warnings_list) == 1
like image 191
Pēteris Caune Avatar answered Oct 22 '22 09:10

Pēteris Caune