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