I am working with code that throws a lot of (for me at the moment) useless warnings using the
warnings library. Reading (/scanning) the documentation I only found a way to disable warnings for single functions. But I don’t want to change so much of the code.
Is there a flag like
python -no-warning foo.py?
What would you recommend?
python -W ignore foo.py
Look at the Temporarily Suppressing Warnings section of the Python docs:
If you are using code that you know will raise a warning, such as a deprecated function, but do not want to see the warning, then it is possible to suppress the warning using the
import warnings def fxn(): warnings.warn("deprecated", DeprecationWarning) with warnings.catch_warnings(): warnings.simplefilter("ignore") fxn()
I don’t condone it, but you could just suppress all warnings with this:
import warnings warnings.filterwarnings("ignore")
>>> import warnings >>> def f(): ... print('before') ... warnings.warn('you are warned!') ... print('after') ... >>> f() before <stdin>:3: UserWarning: you are warned! after >>> warnings.filterwarnings("ignore") >>> f() before after
You can also define an environment variable (new feature in 2010 – i.e. python 2.7)
Test like this: Default
$ export PYTHONWARNINGS="default" $ python >>> import warnings >>> warnings.warn('my warning') __main__:1: UserWarning: my warning >>>
$ export PYTHONWARNINGS="ignore" $ python >>> import warnings >>> warnings.warn('my warning') >>>
For deprecation warnings have a look at how-to-ignore-deprecation-warnings-in-python
From documentation of the
#!/usr/bin/env python -W ignore::DeprecationWarning
If you’re on Windows: pass
-W ignore::DeprecationWarning as an argument to Python. Better though to resolve the issue, by casting to int.
(Note that in Python 3.2, deprecation warnings are ignored by default.)
import warnings with warnings.catch_warnings(): warnings.filterwarnings("ignore", category=DeprecationWarning) import md5, sha yourcode()
Now you still get all the other
DeprecationWarnings, but not the ones caused by:
import md5, sha
warnings are output via stderr and the simple solution is to append ‘2> /dev/null’ to the CLI. this makes a lot of sense to many users such as those with centos 6 that are stuck with python 2.6 dependencies (like yum) and various modules are being pushed to the edge of extinction in their coverage.
this is especially true for cryptography involving SNI et cetera. one can update 2.6 for HTTPS handling using the proc at:
the warning is still in place, but everything you want is back-ported. the re-direct of stderr will leave you with clean terminal/shell output although the stdout content itself does not change.
responding to FriendFX. sentence one (1) responds directly to the problem with an universal solution. sentence two (2) takes into account the cited anchor re ‘disable warnings’ which is python 2.6 specific and notes that RHEL/centos 6 users cannot directly do without 2.6. although no specific warnings were cited, para two (2) answers the 2.6 question I most frequently get re the short-comings in the cryptography module and how one can “modernize” (i.e., upgrade, backport, fix) python’s HTTPS/TLS performance. para three (3) merely explains the outcome of using the re-direct and upgrading the module/dependencies.
This is an old question but there is some newer guidance in PEP 565 that to turn off all warnings if you’re writing a python application you should use:
import sys import warnings if not sys.warnoptions: warnings.simplefilter("ignore")
The reason this is recommended is that it turns off all warnings by default but crucially allows them to be switched back on via
python -W on the command line or
If you don’t want something complicated, then:
import warnings warnings.filterwarnings("ignore", category=FutureWarning)
If you know what are the useless warnings you usually encounter, you can filter them by message.
import warnings #ignore by message warnings.filterwarnings("ignore", message="divide by zero encountered in divide") ##part of the message is also okay warnings.filterwarnings("ignore", message="divide by zero encountered") warnings.filterwarnings("ignore", message="invalid value encountered")
I realise this is only applicable to a niche of the situations, but within a
numpy context I really like using
__main__:1: RuntimeWarning: invalid value encountered in sqrt nan
with np.errstate(invalid='ignore'): np.sqrt(-1)
The best part being you can apply this to very specific lines of code only.
Since ‘warning.filterwarnings()‘ is not suppressing all the warnings, i will suggest you to use the following method:
import logging for name in logging.Logger.manager.loggerDict.keys(): logging.getLogger(name).setLevel(logging.CRITICAL) #rest of the code starts here...
If you want to suppress only a specific set of warnings, then you can filter like this:
import logging for name in logging.Logger.manager.loggerDict.keys(): if ('boto' in name) or ('urllib3' in name) or ('s3transfer' in name) or ('boto3' in name) or ('botocore' in name) or ('nose' in name): logging.getLogger(name).setLevel(logging.CRITICAL) #rest of the code starts here...
import sys if not sys.warnoptions: import warnings warnings.simplefilter("ignore")
default when working on the file or adding new functionality to re-enable warnings.
Not to make it complicated, just use these two lines
import warnings warnings.filterwarnings('ignore')
When all else fails use this: https://github.com/polvoazul/shutup
pip install shutup
then add to the top of your code:
import shutup; shutup.please()
Disclaimer: I am the owner of that repository. I wrote it after the 5th time I needed this and couldn’t find anything simple that just worked.