pip install pipreqs

Obs.: if you don't want support for jupyter notebooks, you can install pipreqs without the dependencies that give support to it. To do so, run:

pip install --no-deps pipreqs pip install yarg==0.1.9 docopt==0.6.2

Usage: pipreqs [options] [<path>] Arguments: <path> The path to the directory containing the application files for which a requirements file should be generated (defaults to the current working directory) Options: --use-local Use ONLY local package info instead of querying PyPI --pypi-server <url> Use custom PyPi server --proxy <url> Use Proxy, parameter will be passed to requests library. You can also just set the environments parameter in your terminal: $ export HTTP_PROXY="http://10.10.1.10:3128" $ export HTTPS_PROXY="https://10.10.1.10:1080" --debug Print debug information --ignore <dirs>... Ignore extra directories, each separated by a comma --ignore-errors Ignore errors when parsing single .py file --no-follow-links Do not follow symbolic links in the project --encoding <charset> Use encoding parameter for file open --savepath <file> Save the list of requirements in the given file --print Output the list of requirements in the standard output --force Overwrite existing requirements.txt --diff <file> Compare modules in requirements.txt to project imports --clean <file> Clean up requirements.txt by removing modules that are not imported in project --mode <scheme> Enables dynamic versioning with <compat>, <gt> or <non-pin> schemes <compat> | e.g. Flask~=1.1.2 <gt> | e.g. Flask>=1.1.2 <no-pin> | e.g. Flask --scan-notebooks Look for imports in jupyter notebook files. 

$ pipreqs /home/project/location Successfully saved requirements file in /home/project/location/requirements.txt 

Contents of requirements.txt

wheel==0.23.0 Yarg==0.1.9 docopt==0.6.2 

• pip freeze only saves the packages that are installed with pip install in your environment.
• pip freeze saves all packages in the environment including those that you don't use in your current project (if you don't have virtualenv).
• and sometimes you just need to create requirements.txt for a new project without installing modules.