How to Suppress a Third-Party Warning Using Warnings. Filterwarnings

Easiest way would be as the warnings module suggests here:

with warnings.catch_warnings():
    warnings.simplefilter("ignore")
    import paramiko

The module argument to warnings.filterwarnings takes a case-sensitive regular expression which should match the fully qualified module name, so

warnings.filterwarnings(
    action='ignore',
    category=DeprecationWarning,
    module=r'.*randpool'
)

or

warnings.filterwarnings(
    action='ignore',
    category=DeprecationWarning,
    module=r'Crypto\.Utils\.randpool'
)

should work. You may need to write RandomPool_DeprecationWarning explicitly instead of DeprecationWarning if for some reason RandomPool_DeprecationWarning is not a subclass of DeprecationWarning.

You can also disable the warning on the command line when you invoke the script by passing the -W option to the interpreter like so:

$ python -W ignore::RandomPool_DeprecationWarning:Crypto.Utils.randpool: my_script.py

The -W takes filters in the format action:message:category:module:lineno, where this time module must exactly match the (fully-qualified) module name where the warning is raised.

See and

To filter only a specific warning:

with warnings.catch_warnings():
    warnings.simplefilter('ignore', SpecificWarningObject)

    #do something that raises a Warning

The most flexible way is to combine warnings.filterwarnings() (or warnings.simplefilter()) with the warnings.catch_warnings() context manager. This way you ge the flexibility of filterwarnings but the filtering is only applied inside the with block:

import warnings

with warnings.catch_warnings():
    warnings.filterwarnings(
        action='ignore',
        category=SomeWarningClass,
        message='some message')
   
    # Do stuff that causes the warning

See The Warnings Filter in the docs for the descriptions of the arguments for filterwarnings.

Full example

Here is a full example with a custom warning:

import warnings

# Custom warning class for the example
class MyWarning(UserWarning):
    pass

def function_that_raises_warning(num):
    print(num)
    warnings.warn("This is a warning", MyWarning)


with warnings.catch_warnings():
    function_that_raises_warning(1) # raises warning
    warnings.filterwarnings(
        action="ignore", category=MyWarning, message="This is a warning"
    )

    function_that_raises_warning(2) # Warning is filtered
function_that_raises_warning(3) # raises warning

Example output

1
.\test_warnings.py:10: MyWarning: This is a warning
  warnings.warn("This is a warning", MyWarning)
2
3
.\test_warnings.py:10: MyWarning: This is a warning
  warnings.warn("This is a warning", MyWarning)