Requirements File Format

Requirements files serve as a list of items to be installed by pip, when using pip install. Files that use this format are often called “pip requirements.txt files”, since requirements.txt is usually what these files are named (although, that is not a requirement).

Example

# This is a comment, to show how #-prefixed lines are ignored.
# It is possible to specify requirements as plain names.
pytest
pytest-cov
beautifulsoup4

# The syntax supported here is the same as that of requirement specifiers.
docopt == 0.6.1
requests [security] >= 2.8.1, == 2.8.* ; python_version < "2.7"
urllib3 @ https://github.com/urllib3/urllib3/archive/refs/tags/1.26.8.zip

# It is possible to refer to other requirement files or constraints files.
-r other-requirements.txt
-c constraints.txt

# It is possible to refer to specific local distribution paths.
./downloads/numpy-1.9.2-cp34-none-win32.whl

# It is possible to refer to URLs.
http://wxpython.org/Phoenix/snapshot-builds/wxPython_Phoenix-3.0.3.dev1820+49a8884-cp34-none-win_amd64.whl

Struct

Each line of the requirements file indicates something to be installed, or arguments to pip install. The following forms are supported:

Line continuations

A line ending in an unescaped \ is treated as a line continuation and the newline following it is effectively ignored.

Comments

A line that begins with # is treated as a comment and ignored. Whitespace followed by a # causes the # and the remainder of the line to be treated as a comment.
Comments are stripped after line continuations are processed.