Add a --save option to install ala npm's save option

What this would do is add the package to the requirements file specified along with the version number of it.

$ cat requirements.txt
old-package==1.0.0

$ pip install new-package --save requirements.txt

# Install logs, installs version 1.5.3 of new-package

$ cat requirements.txt
old-package==1.0.0
new-package==1.5.3

I think it would also be great if it included the dependencies but maybe put a comment in there about them, or maybe that would be another option.

[xiemeilong]

+1

[williamboman]

FWIW; I use the following bash function for saving to ./requirements.txt

pip-save ()
{
    for pkg in $@;
    do
        pip install "$pkg" && {
            name="$(pip show "$pkg" | grep Name: | awk '{print $2}')";
            version="$(pip show "$pkg" | grep Version: | awk '{print $2}')";
            echo "${name}==${version}" >> requirements.txt
        };
    done
}