How to list all installed packages and their versions in Python?

Question

Is there a way in Python to list all installed packages and their versions?

I know I can go inside python/Lib/site-packages and see what files and direc

Answer 1

yes! you should be using pip as your python package manager ( http://pypi.python.org/pypi/pip )

with pip installed packages, you can do a

pip freeze

and it will list all installed packages. You should probably also be using virtualenv and virtualenvwrapper. When you start a new project, you can do

mkvirtualenv my_new_project

and then (inside that virtualenv), do

pip install all_your_stuff

This way, you can workon my_new_project and then pip freeze to see which packages are installed for that virtualenv/project.

for example:

➜  ~  mkvirtualenv yo_dude
New python executable in yo_dude/bin/python
Installing setuptools............done.
Installing pip...............done.
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/get_env_details

(yo_dude)➜  ~  pip install django
Downloading/unpacking django
  Downloading Django-1.4.1.tar.gz (7.7Mb): 7.7Mb downloaded
  Running setup.py egg_info for package django

Installing collected packages: django
  Running setup.py install for django
    changing mode of build/scripts-2.7/django-admin.py from 644 to 755

    changing mode of /Users/aaylward/dev/virtualenvs/yo_dude/bin/django-admin.py to 755
Successfully installed django
Cleaning up...

(yo_dude)➜  ~  pip freeze
Django==1.4.1
wsgiref==0.1.2

(yo_dude)➜  ~  

or if you have a python package with a requirements.pip file,

mkvirtualenv my_awesome_project
pip install -r requirements.pip
pip freeze

will do the trick

Answer 2

To run this in later versions of pip (tested on pip==10.0.1) use the following:

from pip._internal.operations.freeze import freeze
for requirement in freeze(local_only=True):
    print(requirement)

Answer 3

You can try : Yolk

For install yolk, try:

easy_install yolk

Yolk is a Python tool for obtaining information about installed Python packages and querying packages avilable on PyPI (Python Package Index).

You can see which packages are active, non-active or in development mode and show you which have newer versions available by querying PyPI.

Answer 4

If you want to get information about your installed python distributions and don't want to use your cmd console or terminal for it, but rather through python code, you can use the following code (tested with python 3.4):

import pip #needed to use the pip functions
for i in pip.get_installed_distributions(local_only=True):
    print(i)

The pip.get_installed_distributions(local_only=True) function-call returns an iterable and because of the for-loop and the print function the elements contained in the iterable are printed out separated by new line characters (\n). The result will (depending on your installed distributions) look something like this:

cycler 0.9.0
decorator 4.0.4
ipykernel 4.1.0
ipython 4.0.0
ipython-genutils 0.1.0
ipywidgets 4.0.3
Jinja2 2.8
jsonschema 2.5.1
jupyter 1.0.0
jupyter-client 4.1.1
#... and so on...

Answer 5

If this is needed to run from within python you can just invoke subprocess

from subprocess import PIPE, Popen

pip_process = Popen(["pip freeze"], stdout=PIPE,
                   stderr=PIPE, shell=True)
stdout, stderr = pip_process.communicate()
print(stdout.decode("utf-8"))

Answer 6

help('modules') should do it for you.

in IPython :

In [1]: import                      #import press-TAB
Display all 631 possibilities? (y or n)
ANSI                   audiodev               markupbase
AptUrl                 audioop                markupsafe
ArgImagePlugin         avahi                  marshal
BaseHTTPServer         axi                    math
Bastion                base64                 md5
BdfFontFile            bdb                    mhlib
BmpImagePlugin         binascii               mimetools
BufrStubImagePlugin    binhex                 mimetypes
CDDB                   bisect                 mimify
CDROM                  bonobo                 mmap
CGIHTTPServer          brlapi                 mmkeys
Canvas                 bsddb                  modulefinder
CommandNotFound        butterfly              multifile
ConfigParser           bz2                    multiprocessing
ContainerIO            cPickle                musicbrainz2
Cookie                 cProfile               mutagen
Crypto                 cStringIO              mutex
CurImagePlugin         cairo                  mx
DLFCN                  calendar               netrc
DcxImagePlugin         cdrom                  new
Dialog                 cgi                    nis
DiscID                 cgitb                  nntplib
DistUpgrade            checkbox               ntpath