The usage of -m option of python

[Terry Reedy]

On 3/18/2013 11:03 PM, Terry Reedy wrote:
> On 3/18/2013 5:17 PM, Peng Yu wrote:
>> Hi,
>>
>> I don't quite understand how -m option is used. And it is difficult to
>> search for -m in google. Could anybody provide me with an example on
>> how to use this option?
>
> python -m test
> at a command line runs the regression tests in the test package
> python -m test -v test_difflib
> runs test.test_difflib in verbose mode.
>
> These are alternatives to
> python <path-to-test> ...
> Python just searches for module itself, same as for import, but executes
> it as main module instead of importing.
>
> This is really handy for developers running tests, where path-to-test is
> not only a nuisance to type, but different for development builds than
> for installations, and of course, different for each version. Let python
> find the /Lib corresponding to the executable.
>
> I am not sure if it works for things outside /Lib

It does. All startup options are explained in the section "1.1 Command 
line" of the doc "Python Setup and Usage"

The entry for -m starts "Search sys.path for the named module and 
execute its contents as the __main__ module." and continues another 14 
lines.

Along with other startup options, '-m' is indexed on the Symbols page of 
the index.

-- 
Terry Jan Reedy