Is there a way to list pip dependencies/requiremen

Question

Without going through with the installation, I want to quickly see all the packages that pip install would install.

Answer 1

If and only if the package is install, you can use pip show <package>. Look for the Requires: filed at the end of the output. Clearly, this breaks your requirement but might be useful nonetheless.

For example:

$ pip --version
pip 7.1.0 [...]
$ pip show pytest
---
Metadata-Version: 2.0
Name: pytest
Version: 2.7.2
Summary: pytest: simple powerful testing with Python
Home-page: http://pytest.org
Author: Holger Krekel, Benjamin Peterson, Ronny Pfannschmidt, Floris Bruynooghe and others
Author-email: holger at merlinux.eu
License: MIT license
Location: /home/usr/.tox/develop/lib/python2.7/site-packages
Requires: py

Answer 2

Check out johnnydep!

Installation:

pip install johnnydep

Usage example:

$ johnnydep requests
name                       summary
-------------------------  ----------------------------------------------------------------------
requests                   Python HTTP for Humans.
├── certifi>=2017.4.17     Python package for providing Mozilla's CA Bundle.
├── chardet<3.1.0,>=3.0.2  Universal encoding detector for Python 2 and 3
├── idna<2.7,>=2.5         Internationalized Domain Names in Applications (IDNA)
└── urllib3<1.23,>=1.21.1  HTTP library with thread-safe connection pooling, file post, and more.

A more complex tree:

$ johnnydep ipython 
name                              summary
--------------------------------  -----------------------------------------------------------------------------
ipython                           IPython: Productive Interactive Computing
├── appnope                       Disable App Nap on OS X 10.9
├── decorator                     Better living through Python with decorators
├── jedi>=0.10                    An autocompletion tool for Python that can be used for text editors.
│   └── parso==0.1.1              A Python Parser
├── pexpect                       Pexpect allows easy control of interactive console applications.
│   └── ptyprocess>=0.5           Run a subprocess in a pseudo terminal
├── pickleshare                   Tiny 'shelve'-like database with concurrency support
├── prompt-toolkit<2.0.0,>=1.0.4  Library for building powerful interactive command lines in Python
│   ├── six>=1.9.0                Python 2 and 3 compatibility utilities
│   └── wcwidth                   Measures number of Terminal column cells of wide-character codes
├── pygments                      Pygments is a syntax highlighting package written in Python.
├── setuptools>=18.5              Easily download, build, install, upgrade, and uninstall Python packages
├── simplegeneric>0.8             Simple generic functions (similar to Python's own len(), pickle.dump(), etc.)
└── traitlets>=4.2                Traitlets Python config system
    ├── decorator                 Better living through Python with decorators
    ├── ipython-genutils          Vestigial utilities from IPython
    └── six                       Python 2 and 3 compatibility utilities