logging module crashes in Python 2.7.3 for handler.setLevel(long)

[tobinbaker]

BPO	15710
Nosy	@vsajip, @pitrou, @merwok

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2012-08-29.13:34:07.486>
created_at = <Date 2012-08-16.21:33:58.925>
labels = ['type-feature', 'library']
title = 'logging module crashes in Python 2.7.3 for handler.setLevel(long)'
updated_at = <Date 2012-08-29.13:34:07.484>
user = 'https://bugs.python.org/tobinbaker'

bugs.python.org fields:

activity = <Date 2012-08-29.13:34:07.484>
actor = 'python-dev'
assignee = 'none'
closed = True
closed_date = <Date 2012-08-29.13:34:07.486>
closer = 'python-dev'
components = ['Library (Lib)']
creation = <Date 2012-08-16.21:33:58.925>
creator = 'tobin.baker'
dependencies = []
files = []
hgrepos = []
issue_num = 15710
keywords = []
message_count = 7.0
messages = ['168418', '169018', '169019', '169069', '169073', '169077', '169378']
nosy_count = 5.0
nosy_names = ['vinay.sajip', 'pitrou', 'eric.araujo', 'python-dev', 'tobin.baker']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue15710'
versions = ['Python 2.7']

[tobinbaker]

I'm using a 3rd-party library (ESAPI) which defines a log level as the literal -2**31. This worked fine until I upgraded to Python 2.7.3, which, unlike all previous versions of Python, coerces that literal to long rather than int. The following code in the logging module then throws a TypeError:

def _checkLevel(level):
    if isinstance(level, int):
        rv = level
    elif str(level) == level:
        if level not in _levelNames:
            raise ValueError("Unknown level: %r" % level)
        rv = _levelNames[level]
    else:
        raise TypeError("Level not an integer or a valid string: %r" % level)
    return rv

Although this is certainly an unusual use case, it seems that as just a matter of principle, the module should be using the check isinstance(level, (int, long)) rather than just isinstance(level, int).

Here's the relevant part of the traceback:

File "/usr/lib/python2.7/logging/init.py", line 710, in setLevel
self.level = _checkLevel(level)
File "/usr/lib/python2.7/logging/init.py", line 190, in _checkLevel
raise TypeError("Level not an integer or a valid string: %r" % level)
TypeError: Level not an integer or a valid string: -2147483648L

[vsajip]

I don't feel it would be correct to allow long for log levels, since a log level is not intended to have that range. It would be more sensible to get the ESAPI developers to use a more appropriate boundary value; in general, negative log values are not used (they are not necessary).

[pitrou]

This seems to miss the point that it's a regression. int and long are supposed to be interchangeable for most purposes.

[vsajip]

type(-2**31) is long for 2.5 and 2.6 as well as 2.7. The check was added as a response to bpo-6314, to catch incorrect values being passed as levels.

It could be argued that -2**31 is not a sensible log level. While int and long are supposed to be interchangeable for most purposes, isn't this a reasonable case where you shouldn't need to support long? If you feel not, what scenarios do you believe lie outside the "most purposes"?

[pitrou]

type(-2**31) is long for 2.5 and 2.6 as well as 2.7. The check was
added as a response to bpo-6314, to catch incorrect values being passed
as levels.

Well, what is an incorrect value and why would you bother refusing long?
And how about small long values (e.g. long(0))?

[vsajip]

It's not that big a deal, and doesn't matter for 3.x anyway. It just doesn't seem quite right, so I'll make the change soon.

[python-dev]

New changeset 8ba6d8fc9740 by Vinay Sajip in branch '2.7':
Closes bpo-15710: accept long in _checkLevel.
http://hg.python.org/cpython/rev/8ba6d8fc9740