Use poetry instead of pipenv for developer/testing

.github/workflows/ci.yml

@@ -1,8 +1,8 @@
 on:
   push:
-    branches: [ master ]
+    branches: [master]
   pull_request:
-    branches: [ master ]
+    branches: [master]
 
 jobs:
   test:
@@ -13,19 +13,51 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python 3.7
+        id: setup-python
         uses: actions/setup-python@v2
         with:
           python-version: 3.7
-      - name: Install Flair dependencies
-        run: pip install -e .
-      - name: Install unittest dependencies
-        run: pip install -r requirements-dev.txt
-      - name: Show installed dependencies
-        run: pip freeze
+      #----------------------------------------------
+      #       Try to load cached poetry installation
+      #----------------------------------------------
+      - name: Load cached Poetry installation
+        id: cached-poetry
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.local
+            ~/.cache/pypoetry
+          key: poetry-0 # increment to reset cache
+      #----------------------------------------------
+      #       Install poetry if not using cached
+      #----------------------------------------------
+      - name: Install Poetry
+        if: steps.cached-poetry.outputs.cache-hit != 'true'
+        uses: snok/install-poetry@v1
+        with:
+          virtualenvs-in-project: true
+      #----------------------------------------------
+      #       Lock dependencies to get fresh versions
+      #----------------------------------------------
+      - name: Run poetry lock
+        run: poetry lock
+      #----------------------------------------------
+      # install dependencies if cache does not exist
+      #----------------------------------------------
+      - name: Install dependencies
+        run: |
+          poetry config virtualenvs.in-project true
+          poetry install --no-interaction --no-root
+      #----------------------------------------------
+      #              run test suite
+      #----------------------------------------------
       - name: Cache downloaded models/datasets
         uses: actions/cache@v3
         with:
           path: ./cache
           key: cache-v1.1
       - name: Run tests
-        run: pytest --runintegration --durations=0 -vv
+        run: |
+          source .venv/bin/activate
+          python -c 'import flair'
+          pytest --runintegration --durations=0 -vv

.gitignore

@@ -106,7 +106,5 @@ venv.bak/
 # mypy
 .mypy_cache/
 
-Pipfile.lock
-
 resources/taggers/
 regression_train/

CONTRIBUTING.md

@@ -6,21 +6,19 @@ side, please stick to the following process:
 1. Check if there is already [an issue](https://github.com/zalandoresearch/flair/issues) for your concern.
 2. If there is not, open a new one to start a discussion. We hate to close finished PRs!
 3. If we decide your concern needs code changes, we would be happy to accept a pull request. Please consider the
-commit guidelines below.
+   commit guidelines below.
 
 In case you just want to help out and don't know where to start,
 [issues with "help wanted" label](https://github.com/zalandoresearch/flair/labels/help%20wanted) are good for
 first-time contributors.
 
-
 ## Git Commit Guidelines
 
 If there is already a ticket, use this number at the start of your commit message.
 Use meaningful commit messages that described what you did.
 
 **Example:** `GH-42: Added new type of embeddings: DocumentEmbedding.`
 
-
 ## Developing locally
 
 For contributors looking to get deeper into the API we suggest cloning the repository and checking out the unit
@@ -29,48 +27,49 @@ the code should hopefully be easy.
 
 ### Setup
 
-You can either use [Pipenv](https://pipenv.readthedocs.io/) for this:
+Flair requires python-3.7 or higher. To make sure your code also runs on the oldest supported
+python version, it is recommended to use python-3.7.x for flair development.
 
-```bash
-pipenv install --dev && pipenv shell
-```
+We use [poetry](https://python-poetry.org) for dependency and virtual environment management.
+Install poetry following the official guide at https://python-poetry.org/docs/#installation - using the official installer
+or via [pipx](https://pypa.github.io/pipx/).
 
-Or create a python environment of your preference and run:
-```bash
-pip install -r requirements-dev.txt
-```
+After the pre-conditions are met, switch into the checked out flair folder.
 
-### Git pre-commit Hooks
-After installing the dependencies, install `pre-commit` hooks via:
 ```bash
-pre-commit install
-```
+# Install dependencies (including dev dependencies)
+poetry install
 
-This will automatically run code formatters black and isort for each git commit.
+# You can turn on the installed environment
+poetry shell
+```
 
 ### Tests
 
 To only run typechecks and check the code formatting execute:
+
 ```bash
 pytest flair
 ```
 
 To run all basic tests execute:
+
 ```bash
 pytest
 ```
 
 To run integration tests execute:
+
 ```bash
 pytest --runintegration
 ```
+
 The integration tests will train small models and therefore take more time.
 In general, it is recommended to ensure all basic tests are running through before testing the integration tests
 
 ### Code Formatting
 
-To ensure a standardized code style we use the formatter [black](https://github.com/ambv/black) and for standardizing imports we use [isort](https://github.com/PyCQA/isort).
-If your code is not formatted properly, the tests will fail.
-
-If you set up pre-commit hooks, every git commit will automatically run these formatters. Otherwise you can also manually run them, or let your IDE run them on every file save.
-Running from the command line works via `black flair/ && isort flair/` in the flair root folder.
+To ensure a standardized code style we use the formatter [black](https://github.com/ambv/black) and for standardizing
+imports we use [isort](https://github.com/PyCQA/isort). If your code is not formatted properly, the tests will fail.
+We recommend configuring your IDE to run these formatters for you, but you can also always run them manually via
+`black . && isort .` in the flair root folder.