> Thanks for the help, but... I have encountered another problem... here it is :

>     Traceback (most recent call last):
>       File "<string>", line 1, in <module>
>       File "/private/var/folders/7x/_dsd44s94_nft92r9myn3y0h0000gq/T/pip-build-MsWRmL/websockets/setup.py", line 17, in <module>
>         with open(os.path.join(root, 'README'), encoding='utf-8') as f:
>     TypeError: 'encoding' is an invalid keyword argument for this function
    
>     ----------------------------------------
> Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/7x/_dsd44s94_nft92r9myn3y0h0000gq/T/pip-build-MsWRmL/websockets/

> Note : I am running a Mac OS X

Please make sure to run Python3!