The scripts installed by the pip go to a directory (Python Directory) / Scripts, so you do not have to put the entire path in the import it is recommended that this folder be placed in your PATH in the environment variables.
The second (Scripts) directory receives command files when certain packages are installed, so it is very useful addition
Take a look at this guide:
link
It uses Python 2.7 and gives a command to set the variable directly at the prompt:
[Environment]::SetEnvironmentVariable("Path", "$env:Path;C:\Python27\;C:\Python27\Scripts\", "User")