Nested requirements.txt in python
=================================

python requirements text files can in fact depend on each other due to the fact that you can pass pip install arguments right into your file. The trick is to...

Date: February 17, 2022

python requirements text files can in fact depend on each other due to
the fact that you can pass pip install arguments right into your
`requirements.txt` file. The trick is to just prefix the file with a
`-r` flag, just like you would if you were installing it with `pip
install`

## try it out
Lets create two requirements files in a new directory to play with.

``` bash
mkdir requirements-nest
cd requirements-nest
touch requirements.txt requirements_dev.txt
```

Then add the following to each requirements file.

``` txt
# requirements.txt
kedro[pandas.ParquetDataSet]
```

```txt
# requirements_dev.txt
-r requirements.txt
ipython
```

## Installing

Installing requirements_dev.txt will install both ipython and pandas
since it includes the base requirements file.

``` bash
# this will install only pandas
pip install -r requirements.txt

# this will install both ipython and pandas
pip install -r requirements_dev.txt
```

## Links

This is covered in the
[pip user guide](https://pip.pypa.io/en/stable/user_guide/),
but it is not obvious that this can be done in a requirements.txt
file.