How to import requirements.txt from an existing project using Poetry

poetry doesn't support this directly. But if you have a handmade list of required packages (at best without any version numbers), that only contain the main dependencies and not the dependencies of a dependency you could do this:

$ cat requirements.txt|xargs poetry add

I appreciate this might be a bit late but you can just use

poetry add `cat requirements.txt`

I don't have enough reputation to comment but an enhancement to @Liang's answer is to omit the echo and call poetry itself.

cat requirements.txt | grep -E '^[^# ]' | cut -d= -f1 | xargs -n 1 poetry add

In my case, this successfully added packages to the pyproject.toml file.

For reference this is a snippet of my requirements.txt file:

pytz==2020.1  # https://github.com/stub42/pytzpython-slugify==4.0.1  # https://github.com/un33k/python-slugifyPillow==7.2.0  # https://github.com/python-pillow/Pillow

and when calling cat requirements.txt | grep -E '^[^# ]' | cut -d= -f1 (note the omission of xargs -n 1 poetry add for demonstration) it will output the following:

pytzpython-slugifyPillow# NOTE: this will install the latest package - you may or may not want this.

Adding dev dependencies is as simple as adding the -D or --dev argument.

# dev dependancies examplecat requirements-dev.txt | grep -E '^[^# ]' | cut -d= -f1 | xargs -n 1 poetry add -D

Lastly, if your dev requirements install from a parent requirements file, for example:

-r base.txtpackage1package2

Then this will generate errors when poetry runs, however, it will continue past the -r base.txt line and install the packages as expected.

Tested on Linux manjaro with poetry installed as instructed here.