Get a list of packages installed in your current environment with python

Get a list of installed packages

You may want a list of packages installed in your current environment with python. A summary of what to do in such a case.

Command line

If you just want to know the information, you can do the following on the console.

pip freeze
# .. output messages of command (example)
Jinja2==2.7.2
MarkupSafe==0.23
Pygments==1.6
Sphinx==1.2.2
docutils==0.11

programming

If you want to output as List, for example, on some code. You can find out by reading the pip code. (Reference is pip / commands / freeze.py)

from pip.util import get_installed_distributions

skips = ['setuptools', 'pip', 'distribute', 'python', 'wsgiref']
for dist in get_installed_distributions(local_only=True, skip=skips):
    print(dist.project_name, dist.version)

""" output of script
docutils 0.11
Jinja2 2.7.2
MarkupSafe 0.23
Pygments 1.6
Sphinx 1.2.2
"""

If you don't want to depend on pip

Take a look inside pip / util.py.

def get_installed_distributions(local_only=True,
                                skip=stdlib_pkgs,
                                include_editables=True,
                                editables_only=False):
    """
    Return a list of installed Distribution objects.

    If ``local_only`` is True (default), only return installations
    local to the current virtualenv, if in a virtualenv.

    ``skip`` argument is an iterable of lower-case project names to
    ignore; defaults to stdlib_pkgs

    If ``editables`` is False, don't report editables.

    If ``editables_only`` is True , only report editables.

    """
    if local_only:
        local_test = dist_is_local
    else:
        local_test = lambda d: True

    if include_editables:
        editable_test = lambda d: True
    else:
        editable_test = lambda d: not dist_is_editable(d)

    if editables_only:
        editables_only_test = lambda d: dist_is_editable(d)
    else:
        editables_only_test = lambda d: True

    return [d for d in pkg_resources.working_set
            if local_test(d)
            and d.key not in skip
            and editable_test(d)
            and editables_only_test(d)
            ]

After all, I'm just narrowing down the objects in pkg_resources.working_set by conditions. So, if you don't need to narrow down, you can look at pkg_resources.working_set.

import pkg_resources
for dist in pkg_resources.working_set:
    print(dist.project_name, dist.version)

#  output of script
"""
docutils 0.11
Jinja2 2.7.2
MarkupSafe 0.23
pip 1.4.1
Pygments 1.6
setuptools 0.9.8
Sphinx 1.2.2
"""