Mypy Compatible type hints for cycler

.flake8

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+[flake8]
+max-line-length = 88
+select =
+    # flake8 default
+    D, E, F, W,
+ignore =
+    # flake8 default
+    E121,E123,E126,E226,E24,E704,W503,W504,
+    # pydocstyle
+    D100, D101, D102, D103, D104, D105, D106,
+    D200, D202, D204, D205,
+    D301,
+    D400, D401, D403, D404
+    # ignored by pydocstyle numpy docstring convention
+    D107, D203, D212, D213, D402, D413, D415, D416, D417,
+
+exclude =
+    .git
+    build
+    # External files.
+    .tox
+    .eggs
+
+per-file-ignores =
+    setup.py: E402
+force-check = True

.github/workflows/mypy.yml

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+---
+
+name: Mypy
+
+on:
+  push:
+    branches-ignore:
+      - auto-backport-of-pr-[0-9]+
+      - v[0-9]+.[0-9]+.[0-9x]+-doc
+  pull_request:
+
+jobs:
+  test:
+    name: "Mypy"
+    runs-on: ubuntu-20.04
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+
+      - name: Install Python dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools wheel
+          python -m pip install --upgrade mypy
+
+      - name: Install cycler
+        run: |
+          python -m pip install --no-deps .
+
+      - name: Run mypy
+        run: |
+          mypy cycler test_cycler.py