Find all packages installed with easy_install/pip?

Take note that if you have multiple versions of Python installed on your computer, you may have a few versions of pip associated with each.

Depending on your associations, you might need to be very cautious of what pip command you use:

pip3 list 

Worked for me, where I'm running Python3.4. Simply using pip list returned the error The program 'pip' is currently not installed. You can install it by typing: sudo apt-get install python-pip.

As @almenon pointed out, this no longer works and it is not the supported way to get package information in your code. The following raises an exception:

import pip
installed_packages = dict([(package.project_name, package.version) 
                           for package in pip.get_installed_distributions()])

To accomplish this, you can import pkg_resources. Here's an example:

import pkg_resources
installed_packages = dict([(package.project_name, package.version)
                           for package in pkg_resources.working_set])

I'm on v3.6.5

pip freeze lists all installed packages even if not by pip/easy_install. On CentOs/Redhat a package installed through rpm is found.

If you use the Anaconda python distribution, you can use the conda list command to see what was installed by what method:

user@pc:~ $ conda list
# packages in environment at /anaconda3:
#
# Name                    Version                   Build  Channel
_ipyw_jlab_nb_ext_conf    0.1.0            py36h2fc01ae_0
alabaster                 0.7.10           py36h174008c_0
amqp                      2.2.2                     <pip>
anaconda                  5.1.0                    py36_2
anaconda-client           1.6.9                    py36_0

To grab the entries installed by pip (including possibly pip itself):

user@pc:~ $ conda list | grep \<pip
amqp                      2.2.2                     <pip>
astroid                   1.6.2                     <pip>
billiard                  3.5.0.3                   <pip>
blinker                   1.4                       <pip>
ez-setup                  0.9                       <pip>
feedgenerator             1.9                       <pip>

Of course you probably want to just select the first column, which you can do with (excluding pip if needed):

user@pc:~ $ conda list | awk '$3 ~ /pip/ {if ($1 != "pip") print $1}'
amqp        
astroid
billiard
blinker
ez-setup
feedgenerator 

Finally you can grab these values and pip uninstall all of them using the following:

user@pc:~ $ conda list | awk '$3 ~ /pip/ {if ($1 != "pip") print $1}' | xargs pip uninstall -y

Note the use of the -y flag for the pip uninstall to avoid having to give confirmation to delete.

For those who don't have pip installed, I found this quick script on github (works with Python 2.7.13):

import pkg_resources
distros = pkg_resources.AvailableDistributions()
for key in distros:
  print distros[key]

pip list [options] You can see the complete reference here