pip install add to requirements.txt code example

Example 1: install requirements.txt

pip install -r requirements.txt

Example 2: pip freeze requirements.txt

$ env1/bin/pip freeze > requirements.txt
$ env2/bin/pip install -r requirements.txt

Example 3: pip install requirements.txt

pip3 install -r requirements.txt

Example 4: install requirements.txt in pip command

note: yor should be on the same dir as requirements.txt file 

pip install -r requirements.txt