pipdeptree
==========

``pipdeptree`` is a command line utility for displaying the python
packages installed in an environment in form of a dependency
tree. Since ``pip freeze`` shows all dependencies as a flat list,
finding out which are the top level packages and which packages do
they depend on requires some effort. This utility tries to solve this
problem.


Installation
------------

.. code-block:: bash

    $ pip install pipdeptree

.. note:: Needs to be installed inside every virtualenv

If you want to use ``pipdeptree`` to view dependency tree of packages
inside a virtualenv, then it needs to be installed inside that env
even if it's already installed globally.


Usage and examples
------------------

To give you a brief idea, here is the output of ``pipdeptree``
compared with ``pip freeze``:

.. code-block:: bash

    $ pip freeze
    Flask==0.10.1
    Flask-Script==0.6.6
    Jinja2==2.7.2
    -e git+git@github.com:naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy-master
    Mako==0.9.1
    MarkupSafe==0.18
    SQLAlchemy==0.9.1
    Werkzeug==0.9.4
    alembic==0.6.2
    argparse==1.2.1
    ipython==2.0.0
    itsdangerous==0.23
    psycopg2==2.5.2
    redis==2.9.1
    slugify==0.0.1
    wsgiref==0.1.2

And now see what ``pipdeptree`` outputs,

.. code-block:: bash

    $ pipdeptree
    Lookupy==0.1
    wsgiref==0.1.2
    argparse==1.2.1
    psycopg2==2.5.2
    Flask-Script==0.6.6
      - Flask [installed: 0.10.1]
        - Werkzeug [required: >=0.7, installed: 0.9.4]
        - Jinja2 [required: >=2.4, installed: 2.7.2]
          - MarkupSafe [installed: 0.18]
        - itsdangerous [required: >=0.21, installed: 0.23]
    alembic==0.6.2
      - SQLAlchemy [required: >=0.7.3, installed: 0.9.1]
      - Mako [installed: 0.9.1]
        - MarkupSafe [required: >=0.9.2, installed: 0.18]
    ipython==2.0.0
    slugify==0.0.1
    redis==2.9.1


Using pipdeptree to write requirements.txt file
-----------------------------------------------

If you wish to track only the top level packages in your
``requirements.txt`` file, it's possible to do so using `pipdeptree`
by grep-ing only the top-level lines from the output,

.. code-block:: bash

    $ pipdeptree | grep -P '^\w+'
    Lookupy==0.1
    wsgiref==0.1.2
    argparse==1.2.1
    psycopg2==2.5.2
    Flask-Script==0.6.6
    alembic==0.6.2
    ipython==2.0.0
    slugify==0.0.1
    redis==2.9.1

There is a problem here though. The output doesn't mention anything
about `Lookupy` being installed as an editable package (refer to the
output of `pip freeze` above) and information about it's source is
lost. To fix this, `pipdeptree` must be run with a `-f` or `--freeze`
flag.

.. code-block:: bash

    $ pipdeptree -f | grep -P '^[\w0-9\-=.]+'
    -e git+git@github.com:naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy-master
    wsgiref==0.1.2
    argparse==1.2.1
    psycopg2==2.5.2
    Flask-Script==0.6.6
    alembic==0.6.2
    ipython==2.0.0
    slugify==0.0.1
    redis==2.9.1
    
    $ $ pipdeptree -f | grep -P '^[\w0-9\-=.]+' > requirements.txt


Usage
-----

.. code-block:: bash

    $ pipdeptree -h
    usage: pipdeptree [-h] [-a] [-l]

    Dependency tree of the installed python packages

    optional arguments:
      -h, --help        show this help message and exit
      -a, --all         list all deps at top level
      -l, --local-only  If in a virtualenv that has global access donot show
                        globally installed packages


Known Issues
------------

One thing you might have noticed already is that ``flask`` is shown as
a dependency of ``flask-script``, which although correct, sounds a bit
odd. ``flask-script`` is being used here *because* we are using
``flask`` and not the other way around. Same with ``sqlalchemy`` and
``alembic``.  I haven't yet thought about a possible solution to this!
(May be if libs that are "extensions" could be distinguished from the
ones that are "dependencies". Suggestions are welcome.)


License
-------

MIT (See LICENSE)