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

I am trying out Poetry in an existing project. It used pyenv and virtual env originally so I have a requirements.txt file with the project's dependencies.

I want to import the requirements.txt file using Poetry, so that I can load the dependencies for the first time. I've looked through poetry's documentation, but I haven't found a way to do this. Could you help me?

I know that I can add all packages manually, but I was hoping for a more automated process, because there are a lot of packages...

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/pytz
python-slugify==4.0.1  # https://github.com/un33k/python-slugify
Pillow==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:

pytz
python-slugify
Pillow
# 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 example
cat 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.txt

package1
package2

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.

Just use the plain requirements.txt and filter out version numbers with awk:

awk -F '==' '{print $1}' requirements.txt | xargs -n1 poetry add

-F specifies a filter or split point. $1 is the first argument in the split. The input file comes as last argument. Afterwards you can pipe it to poetry add using xargs -n 1 to call poetry add with each line consecutively and not with a space separated string at once. If you want to consume all entries at once just ommit -n 1. Also make sure that a poetry environment is already present.

To just consume the requirements.txt omit the filter and use

awk '{print $1}' requirements.txt | xargs -n1 poetry add

But other tools like cat are fine for that case as well.

The best method I've found is this one:

$ for item in $(cat requirements.txt); do poetry add "${item}"; done

For Powershell:

$reqs = @(cat requirements.txt)
for($i = 0; $i -lt $reqs.length; $i++){poetry add $reqs[i]}

Note this won't ignore comments or anything else in the requirements file. This is strictly taking it as raw text so it expects every line to be a package.

I found none of these answers sufficed so I created one of my own:

https://github.com/src-r-r/python-stanza

It's a new baby, so contributions welcome, but so far it's very cookiecutter-friendly:

• automatically detects a setup.py and fetches project info
• allows multiple requirements.txt files to be specified for either dev dependencies or normal dependencies
• allows the name and version to be overwritten.
• also adds referenced requirements (e.g. -r ./special-requirements.txt) if it's included in a requirements file.

Here's one that works if you have # comments (at the start of a line or at the end of a line) in your requirements file:

poetry add $(sed -e 's/#.*//' -e '/^$/ d' < requirements.txt)

https://www.grymoire.com/Unix/Sed.html#uh-30

One liner:

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

I made a tool poetry-add-requirements.txt just for this. Code

Install it with pipx install poetry-add-requirements.txt,

then run poeareq.

Usage

Run poetry-add-requirements.txt, optionally specify your requirements.txt files and --dev for dev dependencies.

poeareq is provided is an alias to poetry-add-requirements.txt.

$ poeareq --help

usage: poeareq [-h] [-D] [requirements.txt files ...]

Add dependencies specified in requirements.txt to your Poetry project

positional arguments:
  requirements.txt file(s)
                        Path(s) to your requirements.txt file(s) (default: requirements.txt)

options:
  -h, --help            show this help message and exit
  -D, --dev             Add to development dependencies (default: False)

Features

• Auto detect charset of requirements.txt file(s) and feed normalized dependency specs to poetry.
• Stop on first poetry add error.

This is reverse from poetry

poetry export -f requirements.txt --without-hashes > requirements.txt