Support for multiple requirements files

[andy-maier]

There are situations when the requirements are split into different requirements files. An example for that is an extra in a package, so you have your main requirements in one file and the delta requirements in another file. Why does the second file only specify the delta requirements: If setup.py generates its extras_require parameter by reading the requirements file for the extras, that file cannot include the main file and thus will specify only the delta requirements.

pip-missing-reqs today allows specifying the --requirements-file option multiple times, but from what I could figure out, it does not accumulate all these requirements, but simply uses those from the last option specified.

I suggest that when the --requirements-file option is specified multiple times, that the file content gets accumulated, and that would allow in the example above to specify both the main requirements file and the delta file for the extra(s).

If that cannot be implemented, then the behavior with allowing multiple --requirements-file options and then using only the last one should be changed so that it can be specified only once.

[adamtheturtle]

For now, can you do the following (untested)?

cat requirements_0.txt requirements_1.txt | pip-missing-reqs --requirements-file=/dev/fd/0 src/