在不修改第三方代码的情况下禁止警告

Question

We use a third party open source tool and it generates a warning:

DeprecationWarning: The compiler package is deprecated and removed in Python 3.x.

How can I suppress this warning without modifying the third party code?

I know how to use warnings.filter() but I can't use it: I call py.test from the command line, thus no single source code line of my code gets executed before the warning gets created.

Creating a wrapper around the console script is not an option.

Answer 1

You can add a usercustomize or sitecustomize module that calls warnings.filter() . It'll be loaded as the interpreter starts.

See The Customization Modules :

Python provides two hooks to let you customize it: sitecustomize and usercustomize . To see how it works, you need first to find the location of your user site-packages directory. Start Python and run this code:

 >>> import site >>> site.getusersitepackages() '/home/user/.local/lib/python2.7/site-packages' 

Now you can create a file named usercustomize.py in that directory and put anything you want in it. It will affect every invocation of Python, unless it is started with the -s option to disable the automatic import.

sitecustomize works in the same way, but is typically created by an administrator of the computer in the global site-packages directory, and is imported before usercustomize . See the documentation of the site module for more details.

You can influence where Python looks with the PYTHONUSERBASE environment variable , so you can point Python to a per-project usercustomize.py file here, provided you take into account the path lib/python/site-packages is added to the base:

$ python -m site --user-site
/Users/someuser/Library/Python/2.7/lib/python/site-packages
$ PYTHONUSERBASE=/foo/bar python -m site --user-site
/foo/bar/lib/python/site-packages

In the above example, with PYTHONUSERBASE set to /foo/bar , Python will load /foo/bar/lib/python/site-packages/usercustomize.py if it exists.

In a Python virtualenv a customised site.py file is used that is based on a site.py from before Python 2.6; this version omits the getusersitepackages() function. If the file lib/pythonX.X/no-global-site-packages.txt exists, the usercustomize module will not be imported. You'll have to use a sitecustomize.py file in the virtual env lib/python/site-packages directory instead.