How do I get a list of locally installed Python modules?

Question

How do I get a list of Python modules installed on my computer?

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Answer 1

From the shell

ls site-packages

If that’s not helpful, you can do this.

import sys
import os
for p in sys.path:
    print os.listdir( p )

And see what that produces.

Answered By: S.Lott

Answer 2

help('modules')

in a Python shell/prompt.

Answered By: ChristopheD

Answer 3

Now, these methods I tried myself, and I got exactly what was advertised: All the modules.

Alas, really you don’t care much about the stdlib, you know what you get with a python install.

Really, I want the stuff that I installed.

What actually, surprisingly, worked just fine was:

pip freeze

Which returned:

Fabric==0.9.3
apache-libcloud==0.4.0
bzr==2.3b4
distribute==0.6.14
docutils==0.7
greenlet==0.3.1
ipython==0.10.1
iterpipes==0.4
libxml2-python==2.6.21

I say “surprisingly” because the package install tool is the exact place one would expect to find this functionality, although not under the name ‘freeze’ but python packaging is so weird, that I am flabbergasted that this tool makes sense. Pip 0.8.2, Python 2.7.

Answered By: chiggsy

Answer 4

In ipython you can type “importTab“.
In the standard Python interpreter, you can type “help('modules')“.
At the command-line, you can use pydoc modules.
In a script, call pkgutil.iter_modules().

Answered By: johnsyweb

Answer 5

Very simple searching using pkgutil.iter_modules

from pkgutil import iter_modules
a=iter_modules()
while True:
    try: x=a.next()
    except: break
    if 'searchstr' in x[1]: print x[1]

Answered By: stuudent

Answer 6

I just use this to see currently used modules:

import sys as s
s.modules.keys()

which shows all modules running on your python.

For all built-in modules use:

s.modules

Which is a dict containing all modules and import objects.

Answered By: Dan Evans

Answer 7

I ran into a custom installed python 2.7 on OS X. It required X11 to list modules installed (both using help and pydoc).

To be able to list all modules without installing X11 I ran pydoc as http-server, i.e.:

pydoc -p 12345

Then it’s possible to direct Safari to http://localhost:12345/ to see all modules.

Answered By: Qiau

Answer 8

Aside from using pip freeze I have been installing yolk in my virtual environments.

Answered By: jdsantiagojr

Answer 9

Since pip version 1.3, you’ve got access to:

pip list

Which seems to be syntactic sugar for “pip freeze”. It will list all of the modules particular to your installation or virtualenv, along with their version numbers. Unfortunately it does not display the current version number of any module, nor does it wash your dishes or shine your shoes.

Answered By: Bryce

Answer 10

In normal shell just use

pydoc modules

Answered By: DrkNess

Answer 11

In case you have an anaconda python distribution installed, you could also use

$conda list

in addition to solutions described above.

Answered By: Shreyas

Answer 12

If we need to list the installed packages in the Python shell, we can use the help command as follows

>>> help('modules package')

Answered By: Sadheesh

Answer 13

to get all available modules, run sys.modules
to get all installed modules (read: installed by pip), you may look at pip.get_installed_distributions()

For the second purpose, example code:

import pip
for package in pip.get_installed_distributions():
    name = package.project_name # SQLAlchemy, Django, Flask-OAuthlib
    key = package.key # sqlalchemy, django, flask-oauthlib
    module_name = package._get_metadata("top_level.txt") # sqlalchemy, django, flask_oauthlib
    location = package.location # virtualenv lib directory etc.
    version = package.version # version number

Answered By: yegle

Answer 14

Solution

Do not use with pip > 10.0!

My 50 cents for getting a pip freeze-like list from a Python script:

import pip
installed_packages = pip.get_installed_distributions()
installed_packages_list = sorted(["%s==%s" % (i.key, i.version)
     for i in installed_packages])
print(installed_packages_list)

As a (too long) one liner:

sorted(["%s==%s" % (i.key, i.version) for i in pip.get_installed_distributions()])

Giving:

['behave==1.2.4', 'enum34==1.0', 'flask==0.10.1', 'itsdangerous==0.24', 
 'jinja2==2.7.2', 'jsonschema==2.3.0', 'markupsafe==0.23', 'nose==1.3.3', 
 'parse-type==0.3.4', 'parse==1.6.4', 'prettytable==0.7.2', 'requests==2.3.0',
 'six==1.6.1', 'vioozer-metadata==0.1', 'vioozer-users-server==0.1', 
 'werkzeug==0.9.4']

Scope

This solution applies to the system scope or to a virtual environment scope, and covers packages installed by setuptools, pip and (god forbid) easy_install.

My use case

I added the result of this call to my flask server, so when I call it with http://example.com/exampleServer/environment I get the list of packages installed on the server’s virtualenv. It makes debugging a whole lot easier.

Caveats

I have noticed a strange behaviour of this technique – when the Python interpreter is invoked in the same directory as a setup.py file, it does not list the package installed by setup.py.

Steps to reproduce:

Create a virtual environment

$ cd /tmp
$ virtualenv test_env
New python executable in test_env/bin/python
Installing setuptools, pip...done.
$ source test_env/bin/activate
(test_env) $

Clone a git repo with setup.py

(test_env) $ git clone https://github.com/behave/behave.git
Cloning into 'behave'...
remote: Reusing existing pack: 4350, done.
remote: Total 4350 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (4350/4350), 1.85 MiB | 418.00 KiB/s, done.
Resolving deltas: 100% (2388/2388), done.
Checking connectivity... done.

We have behave’s setup.py in /tmp/behave:

(test_env) $ ls /tmp/behave/setup.py
/tmp/behave/setup.py

Install the python package from the git repo

(test_env) $ cd /tmp/behave && pip install . 
running install
...
Installed /private/tmp/test_env/lib/python2.7/site-packages/enum34-1.0-py2.7.egg
Finished processing dependencies for behave==1.2.5a1

If we run the aforementioned solution from `/tmp`

>>> import pip
>>> sorted(["%s==%s" % (i.key, i.version) for i in pip.get_installed_distributions()])
['behave==1.2.5a1', 'enum34==1.0', 'parse-type==0.3.4', 'parse==1.6.4', 'six==1.6.1']
>>> import os
>>> os.getcwd()
'/private/tmp'

If we run the aforementioned solution from `/tmp/behave`

>>> import pip
>>> sorted(["%s==%s" % (i.key, i.version) for i in pip.get_installed_distributions()])
['enum34==1.0', 'parse-type==0.3.4', 'parse==1.6.4', 'six==1.6.1']
>>> import os
>>> os.getcwd()
'/private/tmp/behave'

behave==1.2.5a1 is missing from the second example, because the working directory contains behave‘s setup.py file.

I could not find any reference to this issue in the documentation. Perhaps I shall open a bug for it.

Answered By: Adam Matan

Answer 15

on windows, Enter this in cmd

c:pythonlibs>python -m pip freeze

Answered By: Saurabh

Answer 16

pip freeze does it all finding packages however one can simply write the following command to list all paths where python packages are.

>>> import site; site.getsitepackages()
['/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages']

Answered By: Pavan Gupta

Answer 17

This solution is primary based on modules importlib and pkgutil and work with CPython 3.4 and CPython 3.5, but has no support for the CPython 2.

Explanation

sys.builtin_module_names – names all built-in modules (look my answer here)
pkgutil.iter_modules() – returns an information about all available modules
importlib.util.find_spec() – returns an information about importing module, if exists
BuiltinImporter – an importer for built-in modules (docs)
SourceFileLoader – an importer for a standard Python module (by default has extension *.py) (docs)
ExtensionFileLoader – an importer for modules as shared library (written on the C or C++)

Full code

import sys
import os
import shutil
import pkgutil
import importlib
import collections

if sys.version_info.major == 2:
    raise NotImplementedError('CPython 2 is not supported yet')


def main():

    # name this file (module)
    this_module_name = os.path.basename(__file__).rsplit('.')[0]

    # dict for loaders with their modules
    loaders = collections.OrderedDict()

    # names`s of build-in modules
    for module_name in sys.builtin_module_names:

        # find an information about a module by name
        module = importlib.util.find_spec(module_name)

        # add a key about a loader in the dict, if not exists yet
        if module.loader not in loaders:
            loaders[module.loader] = []

        # add a name and a location about imported module in the dict
        loaders[module.loader].append((module.name, module.origin))

    # all available non-build-in modules
    for module_name in pkgutil.iter_modules():

        # ignore this module
        if this_module_name == module_name[1]:
            continue

        # find an information about a module by name
        module = importlib.util.find_spec(module_name[1])

        # add a key about a loader in the dict, if not exists yet
        loader = type(module.loader)
        if loader not in loaders:
            loaders[loader] = []

        # add a name and a location about imported module in the dict
        loaders[loader].append((module.name, module.origin))

    # pretty print
    line = '-' * shutil.get_terminal_size().columns
    for loader, modules in loaders.items():
        print('{0}n{1}: {2}n{0}'.format(line, len(modules), loader))
        for module in modules:
            print('{0:30} | {1}'.format(module[0], module[1]))


if __name__ == '__main__':
    main()

Usage

For the CPython3.5 (truncated)

$ python3.5 python_modules_info.py 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
30: <class '_frozen_importlib.BuiltinImporter'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
_ast                           | built-in
_codecs                        | built-in
_collections                   | built-in
_functools                     | built-in
_imp                           | None
_io                            | built-in
_locale                        | built-in
_operator                      | built-in
_signal                        | built-in
_sre                           | built-in
_stat                          | built-in
_string                        | built-in
_symtable                      | built-in
_thread                        | built-in
(****************************truncated*******************************)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
227: <class '_frozen_importlib_external.SourceFileLoader'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
__future__                     | /usr/local/lib/python3.5/__future__.py
_bootlocale                    | /usr/local/lib/python3.5/_bootlocale.py
_collections_abc               | /usr/local/lib/python3.5/_collections_abc.py
_compat_pickle                 | /usr/local/lib/python3.5/_compat_pickle.py
_compression                   | /usr/local/lib/python3.5/_compression.py
_dummy_thread                  | /usr/local/lib/python3.5/_dummy_thread.py
_markupbase                    | /usr/local/lib/python3.5/_markupbase.py
_osx_support                   | /usr/local/lib/python3.5/_osx_support.py
_pydecimal                     | /usr/local/lib/python3.5/_pydecimal.py
_pyio                          | /usr/local/lib/python3.5/_pyio.py
_sitebuiltins                  | /usr/local/lib/python3.5/_sitebuiltins.py
(****************************truncated*******************************)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
64: <class '_frozen_importlib_external.ExtensionFileLoader'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
_bisect                        | /usr/local/lib/python3.5/lib-dynload/_bisect.cpython-35m-x86_64-linux-gnu.so
_bz2                           | /usr/local/lib/python3.5/lib-dynload/_bz2.cpython-35m-x86_64-linux-gnu.so
_codecs_cn                     | /usr/local/lib/python3.5/lib-dynload/_codecs_cn.cpython-35m-x86_64-linux-gnu.so
_codecs_hk                     | /usr/local/lib/python3.5/lib-dynload/_codecs_hk.cpython-35m-x86_64-linux-gnu.so
_codecs_iso2022                | /usr/local/lib/python3.5/lib-dynload/_codecs_iso2022.cpython-35m-x86_64-linux-gnu.so
(****************************truncated*******************************)

For the CPython3.4 (truncated)

$ python3.4 python_modules_info.py
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
54: <class '_frozen_importlib.BuiltinImporter'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
_ast                           | built-in
_bisect                        | built-in
_codecs                        | built-in
_collections                   | built-in
_datetime                      | built-in
_elementtree                   | built-in
_functools                     | built-in
_heapq                         | built-in
_imp                           | None
_io                            | built-in
_locale                        | built-in
_md5                           | built-in
_operator                      | built-in
_pickle                        | built-in
_posixsubprocess               | built-in
_random                        | built-in
(****************************truncated*******************************)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
246: <class '_frozen_importlib.SourceFileLoader'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
__future__                     | /usr/lib/python3.4/__future__.py
_bootlocale                    | /usr/lib/python3.4/_bootlocale.py
_collections_abc               | /usr/lib/python3.4/_collections_abc.py
_compat_pickle                 | /usr/lib/python3.4/_compat_pickle.py
_dummy_thread                  | /usr/lib/python3.4/_dummy_thread.py
_markupbase                    | /usr/lib/python3.4/_markupbase.py
_osx_support                   | /usr/lib/python3.4/_osx_support.py
_pyio                          | /usr/lib/python3.4/_pyio.py
(****************************truncated*******************************)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
44: <class '_frozen_importlib.ExtensionFileLoader'>
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
_bz2                           | /usr/lib/python3.4/lib-dynload/_bz2.cpython-34m-x86_64-linux-gnu.so
_codecs_cn                     | /usr/lib/python3.4/lib-dynload/_codecs_cn.cpython-34m-x86_64-linux-gnu.so
_codecs_hk                     | /usr/lib/python3.4/lib-dynload/_codecs_hk.cpython-34m-x86_64-linux-gnu.so
_codecs_iso2022                | /usr/lib/python3.4/lib-dynload/_codecs_iso2022.cpython-34m-x86_64-linux-gnu.so
_codecs_jp                     | /usr/lib/python3.4/lib-dynload/_codecs_jp.cpython-34m-x86_64-linux-gnu.so
_codecs_kr                     | /usr/lib/python3.4/lib-dynload/_codecs_kr.cpython-34m-x86_64-linux-gnu.so
_codecs_tw                     | /usr/lib/python3.4/lib-dynload/_codecs_tw.cpython-34m-x86_64-linux-gnu.so
_crypt                         | /usr/lib/python3.4/lib-dynload/_crypt.cpython-34m-x86_64-linux-gnu.so
(****************************truncated*******************************)

Answered By: PADYMKO

Answer 18

As of pip 10, the accepted answer will no longer work. The development team has removed access to the get_installed_distributions routine. There is an alternate function in the setuptools for doing the same thing. Here is an alternate version that works with pip 10:

import pkg_resources
installed_packages = pkg_resources.working_set
installed_packages_list = sorted(["%s==%s" % (i.key, i.version)
     for i in installed_packages])
print(installed_packages_list)

Please let me know if it will or won’t work in previous versions of pip, too.

Answered By: Big_Al_Tx

Answer 19

I normally use pip list to get a list of packages (with version).

This works in a virtual environment too, of course. To show what’s installed in only the virtual environment (not global packages), use pip list --local.

Here’s documentation showing all the available pip list options, with several good examples.

Answered By: James

Answer 20

There are many ideas, initially I am pondering on these two:

pip

cons: not always installed

help(‘modules’)

cons: output to console; with broken modules (see ubuntu…) can segfault

I need an easy approach, using basic libraries and compatible with old python 2.x

And I see the light: listmodules.py

Hidden in the documentation source directory in 2.5 is a small script that lists all available modules for a Python installation.

Pros:

uses only imp, sys, os, re, time

designed to run on Python 1.5.2 and newer

the source code is really compact, so you can easy tinkering with it, for example to pass an exception list of buggy modules (don’t try to import them)

Answered By: Massimo

Answer 21

Warning: Adam Matan discourages this use in pip > 10.0. Also, read @sinoroc’s comment below

This was inspired by Adam Matan’s answer (the accepted one):

import tabulate
try:
  from pip import get_installed_distributions
except:
  from pip._internal.utils.misc import get_installed_distributions

tabpackages = []
for _, package in sorted([('%s %s' % (i.location, i.key), i) for i in get_installed_distributions()]):
  tabpackages.append([package.location, package.key, package.version])

print(tabulate.tabulate(tabpackages))

which then prints out a table in the form of

19:33 pi@rpi-v3 [iot-wifi-2] ~/python$ python installed_packages.py
-------------------------------------------  --------------  ------
/home/pi/.local/lib/python2.7/site-packages  enum-compat     0.0.2
/home/pi/.local/lib/python2.7/site-packages  enum34          1.1.6
/home/pi/.local/lib/python2.7/site-packages  pexpect         4.2.1
/home/pi/.local/lib/python2.7/site-packages  ptyprocess      0.5.2
/home/pi/.local/lib/python2.7/site-packages  pygatt          3.2.0
/home/pi/.local/lib/python2.7/site-packages  pyserial        3.4
/usr/local/lib/python2.7/dist-packages       bluepy          1.1.1
/usr/local/lib/python2.7/dist-packages       click           6.7
/usr/local/lib/python2.7/dist-packages       click-datetime  0.2
/usr/local/lib/python2.7/dist-packages       construct       2.8.21
/usr/local/lib/python2.7/dist-packages       pyaudio         0.2.11
/usr/local/lib/python2.7/dist-packages       tabulate        0.8.2
-------------------------------------------  --------------  ------

which lets you then easily discern which packages you installed with and without sudo.

A note aside: I’ve noticed that when I install a packet once via sudo and once without, one takes precedence so that the other one isn’t being listed (only one location is shown). I believe that only the one in the local directory is then listed. This could be improved.

Answered By: Daniel F

Answer 22

There are many way to skin a cat.

The most simple way is to use the pydoc function directly from the shell with:
pydoc modules
But for more information use the tool called pip-date that also tell you the installation dates.
pip install pip-date

Answered By: not2qubit

Answer 23

I needed to find the specific version of packages available by default in AWS Lambda. I did so with a mashup of ideas from this page. I’m sharing it for posterity.

import pkgutil

__version__ = '0.1.1'

def get_ver(name):
    try:
        return str(__import__(name).__version__)
    except:
        return None

def lambda_handler(event, context):
    return {
        'statusCode': 200,
        'body': [{
                   'path': m.module_finder.path,
                   'name': m.name,
                   'version': get_ver(m.name),
                 } for m in list(pkgutil.iter_modules())
                 #if m.module_finder.path == "/var/runtime" # Uncomment this if you only care about a certain path
                ],
    }

What I discovered is that the provided boto3 library was way out of date and it wasn’t my fault that my code was failing. I just needed to add boto3 and botocore to my project. But without this I would have been banging my head thinking my code was bad.

{
  "statusCode": 200,
  "body": [
    {
      "path": "/var/task",
      "name": "lambda_function",
      "version": "0.1.1"
    },
    {
      "path": "/var/runtime",
      "name": "bootstrap",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "boto3",
      "version": "1.9.42"
    },
    {
      "path": "/var/runtime",
      "name": "botocore",
      "version": "1.12.42"
    },
    {
      "path": "/var/runtime",
      "name": "dateutil",
      "version": "2.7.5"
    },
    {
      "path": "/var/runtime",
      "name": "docutils",
      "version": "0.14"
    },
    {
      "path": "/var/runtime",
      "name": "jmespath",
      "version": "0.9.3"
    },
    {
      "path": "/var/runtime",
      "name": "lambda_runtime_client",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "lambda_runtime_exception",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "lambda_runtime_marshaller",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "s3transfer",
      "version": "0.1.13"
    },
    {
      "path": "/var/runtime",
      "name": "six",
      "version": "1.11.0"
    },
    {
      "path": "/var/runtime",
      "name": "test_bootstrap",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "test_lambda_runtime_client",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "test_lambda_runtime_marshaller",
      "version": null
    },
    {
      "path": "/var/runtime",
      "name": "urllib3",
      "version": "1.24.1"
    },
    {
      "path": "/var/lang/lib/python3.7",
      "name": "__future__",
      "version": null
    },
...

What I discovered was also different from what they officially publish. At the time of writing this:

Operating system – Amazon Linux

AMI – amzn-ami-hvm-2017.03.1.20170812-x86_64-gp2

Linux kernel – 4.14.77-70.59.amzn1.x86_64

AWS SDK for JavaScript – 2.290.0

SDK for Python (Boto 3) – 3-1.7.74 botocore-1.10.74

Answered By: Bruno Bronosky

Answer 24

Try these

pip list

or

pip freeze

Answered By: Amit Gupta

Answer 25

For anyone wondering how to call pip list from a Python program you can use the following:

import pip
pip.main(['list])  # this will print all the packages

Answered By: Marcelo Villa-Piñeros

Answer 26

This will help

In terminal or IPython, type:

help('modules')

then

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

Answered By: Abdullah Akhtar

Answer 27

Installation

pip install pkgutil

Code

import pkgutil

for i in pkgutil.iter_modules(None): # returns a tuple (path, package_name, ispkg_flag)
    print(i[1]) #or you can append it to a list

Sample Output:

multiprocessing
netrc
nntplib
ntpath
nturl2path
numbers
opcode
pickle
pickletools
pipes
pkgutil

Answered By: Sachin Prabhu

Answer 28

Here is a python code solution that will return a list of modules installed. One can easily modify the code to include version numbers.

import subprocess
import sys
from pprint import pprint

installed_packages = reqs = subprocess.check_output([sys.executable, '-m', 'pip', 'freeze']).decode('utf-8')
installed_packages = installed_packages.split('rn')
installed_packages = [pkg.split('==')[0] for pkg in installed_packages if pkg != '']
pprint(installed_packages)

Answered By: Elijah

Answer 29

Works Regardless of Pip Version

Run the following in your python editor or IPython:

import pkg_resources
installed_packages = {d.project_name: d.version for d in pkg_resources.working_set}
print(installed_packages)

Read other answers and pulled together this combo, which is quickest and easiest inside Python.

Find the specific Packages

Conveniently you can then get items from your dict easily, i.e.

installed_packages['pandas'] >> ‘1.16.4’

Using Pip List Well

!pip list will run inside your jupyter notebook if working there, simplifying the ‘quick check’
Combine with other utilities like grep(if you have installed)
pip list | grep pandas will get you your current pandas version for example

Answered By: jabberwocky

Answer 30

If none of the above seem to help, in my environment was broken from a system upgrade and I could not upgrade pip. While it won’t give you an accurate list you can get an idea of which libraries were installed simply by looking inside your env>lib>python(version here)>site-packages> . Here you will get a good indication of modules installed.

Answered By: Josh

Answer 31

pip install pip-chill 
pip-chill

Answered By: Santle Camilus

Answer 32

pip3 freeze

run this command globally – will show you all the global installations
run this command on the virtual environment – will show you all the local installations

Answered By: Artur

Answer 33

I’m comparing five methods to retrieve installed "modules", all of which I’ve seen in this thread

	iter_modules	help("modules")	builtin_module_names	pip list	working_set
Includes distributions	❌	❌	❌	✔️	✔️
Includes modules (No built-in)	✔️	✔️	❌	❌	❌
Includes built-in modules	❌	✔️	✔️	❌	❌
Includes frozen	✔️	✔️	❌	❌	❌
Includes venv	✔️	✔️	❌	✔️	✔️
Includes global	✔️	✔️	❌	✔️	✔️
Includes editable installs	✔️	✔️	❌	✔️	✔️
Includes PyCharm helpers	✔️	❌	❌	❌	❌
Lowers capital letters	❌	❌	❌	❌	✔️
Time taken (665 modules total)	53.7 msec	1.03 sec	577 nsec	284 msec	36.2 usec

Summary

pip list and working_set are for distributions, not modules.
iter_modules and help("modules") are very similar, the biggest difference is that iter_modules doesn’t include built-in.
pip list and working_set are very similar, only difference is that working_set lowers all capital letters.
Built-in modules are only included by help("modules") and builtin_module_names.

Related caveats

Distributions, packages, and modules often have identical names making it easy to mistake one for the other.
importlib.util.find_spec is for modules and is case-sensitive.
sys.modules only lists imported modules.

Distributions

I’m saying distribution instead of package because I think it will reduce misunderstandings. A distribution/package can have multiple packages/modules inside it.

An installed distribution is not always importable by the same name. For example pip install Pillow is imported with import PIL. Sometimes a distribution even makes multiple modules importable.

Methods (Each column in order)

iter_modules

import pkgutil
{module.name for module in pkgutil.iter_modules()}

help("modules") (Only prints in terminal)

help("modules")

builtin_module_names

import sys
set(sys.builtin_module_names)

pip list (Only prints in terminal)

pip list in terminal

working_set

import pkg_resources
{pkg.key for pkg in pkg_resources.working_set}

Conclusion

For terminal I recommend help("modules") or python -c "help('modules')".
- Top voted answer in this thread
For programmatically I recommend iter_modules + builtin_module_names.
- This answer in this thread
  - It is however very convoluted with information, see my minimal example below.

import sys
import pkgutil

def get_installed_modules_names():
    iter_modules = {module.name for module in pkgutil.iter_modules()}
    builtin = sys.builtin_module_names
    return set.union(iter_modules, builtin)

Answered By: Mandera

How do I get a list of locally installed Python modules?

Question:

Answers:

Solution

Do not use with pip > 10.0!

Scope

My use case

Caveats

Steps to reproduce:

If we run the aforementioned solution from `/tmp`

If we run the aforementioned solution from `/tmp/behave`

This will help

Works Regardless of Pip Version

Find the specific Packages

Using Pip List Well

Summary

Related caveats

Distributions

Methods (Each column in order)

iter_modules

help("modules") (Only prints in terminal)

builtin_module_names

pip list (Only prints in terminal)

working_set

Conclusion

How do I get a list of locally installed Python modules?

Question:

Answers:

Solution

Do not use with pip > 10.0!

Scope

My use case

Caveats

Steps to reproduce:

If we run the aforementioned solution from /tmp

If we run the aforementioned solution from /tmp/behave

This will help

Works Regardless of Pip Version

Find the specific Packages

Using Pip List Well

Summary

Related caveats

Distributions

Methods (Each column in order)

iter_modules

help("modules") (Only prints in terminal)

builtin_module_names

pip list (Only prints in terminal)

working_set

Conclusion

If we run the aforementioned solution from `/tmp`

If we run the aforementioned solution from `/tmp/behave`