pip install pipreqs 

Usage: pipreqs <path> [options] Options: --savepath Supply custom path for requirements.txt --debug See debug output 

$ pipreqs /home/project/location Looking for imports Getting latest version of packages information from PyPi Found third-party imports: flask, requests, sqlalchemy, docopt Successfuly saved requirements file in: /home/project/location/requirements.txt 

• 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.