Require Python 3.6

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2.1
 jobs:
   build:
     docker:
-      - image: circleci/python:3.6-buster
+      - image: circleci/python:3.7-buster
     working_directory: /home/circleci/tskit
     steps:
       - checkout
@@ -11,7 +11,7 @@ jobs:
           # It's sometimes necessary to nuke the cache, and the simplest
           # way to do it is to change the key. We can increment this
           # version number when we want to do this.
-          key: tskit-{{ .Branch }}-v1
+          key: tskit-{{ .Branch }}-v4
       - run:
           name: Checkout submodules
           command: |
@@ -23,6 +23,7 @@ jobs:
             libgsl-dev
             # Install meson to the system packages so we can run it as root
             sudo pip install meson==0.55
+            pip install numpy==1.19.5
             pip install --user -r python/requirements/CI-complete/requirements.txt
             pip install twine --user
             # Remove tskit installed by msprime

.github/workflows/docker/shared.env

@@ -2,5 +2,4 @@ PYTHON_VERSIONS=(
     cp39-cp39
     cp38-cp38
     cp37-cp37m
-    cp36-cp36m
 )

.github/workflows/tests.yml

@@ -29,7 +29,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python: [ 3.6, 3.9 ]
+        python: [ 3.7, 3.9 ]
         os:  [ macos-latest, ubuntu-latest, windows-latest ]
     defaults:
       run:

.github/workflows/wheels.yml

@@ -9,13 +9,14 @@ on:
       - '*'
   release:
     types: [published]
+  pull_request:
 
 jobs:
   OSX:
     runs-on: macos-latest
     strategy:
       matrix:
-        python: [3.6, 3.7, 3.8, 3.9]
+        python: [3.7, 3.8, 3.9]
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -57,7 +58,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        python: [3.6, 3.7, 3.8, 3.9]
+        python: [3.7, 3.8, 3.9]
         wordsize: [64]
     steps:
       - name: Checkout
@@ -146,7 +147,7 @@ jobs:
     runs-on: macos-latest
     strategy:
       matrix:
-        python: [3.6, 3.7, 3.8, 3.9]
+        python: [3.7, 3.8, 3.9]
     steps:
       - name: Download wheels
         uses: actions/download-artifact@v2
@@ -168,7 +169,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        python: [3.6, 3.7, 3.8, 3.9]
+        python: [3.7, 3.8, 3.9]
         wordsize: [64]
     steps:
       - name: Download wheels
@@ -191,7 +192,7 @@ jobs:
     needs: ['manylinux']
     strategy:
       matrix:
-        python: [3.6, 3.7, 3.8, 3.9]
+        python: [3.7, 3.8, 3.9]
     steps:
       - name: Download wheels
         uses: actions/download-artifact@v2

.mergify.yml

@@ -7,11 +7,11 @@ pull_request_rules:
       - label=AUTOMERGE-REQUESTED
       - status-success=Docs
       - status-success=Lint
-      - status-success=Python (3.6, macos-latest)
+      - status-success=Python (3.7, macos-latest)
       - status-success=Python (3.9, macos-latest)
-      - status-success=Python (3.6, ubuntu-latest)
+      - status-success=Python (3.7, ubuntu-latest)
       - status-success=Python (3.9, ubuntu-latest)
-      - status-success=Python (3.6, windows-latest)
+      - status-success=Python (3.7, windows-latest)
       - status-success=Python (3.9, windows-latest)
       - "status-success=ci/circleci: build"
       #- status-success=codecov/patch

.pre-commit-config.yaml

@@ -23,7 +23,7 @@ repos:
     rev: v2.7.4
     hooks:
       - id: pyupgrade
-        args: [--py3-plus, --py36-plus]
+        args: [--py3-plus, --py37-plus]
   - repo: https://github.com/psf/black
     rev: 20.8b1
     hooks:

docs/development.rst

@@ -60,7 +60,7 @@ Requirements
 ------------
 
 To develop the Python code you will need a working C compiler and a
-development installation of Python (>= 3.6). On Debian/Ubuntu we can install these
+development installation of Python (>= 3.7). On Debian/Ubuntu we can install these
 with::
 
     $ sudo apt install python3-dev build-essential doxygen
@@ -416,7 +416,7 @@ This is most easily done using ``make``:
 
 If this has completed successfully you should see a file ``_tskit.cpython-XXXXXX.so``
 in the current directory (the suffix depends on your platform and Python version;
-with Python 3.6 on Linux it's ``_tskit.cpython-36m-x86_64-linux-gnu.so``).
+with Python 3.7 on Linux it's ``_tskit.cpython-37m-x86_64-linux-gnu.so``).
 
 To make sure that your development environment is working, run some
 :ref:`tests <sec_development_python_tests>`.

docs/installation.rst

@@ -18,7 +18,7 @@ so it may already be installed if you use such software.
 Requirements
 ************
 
-Tskit requires Python 3.6+. There are no external C library dependencies. Python
+Tskit requires Python 3.7+. There are no external C library dependencies. Python
 dependencies are installed automatically by ``pip`` or ``conda``.
 
 .. _sec_installation_conda:

python/CHANGELOG.rst

@@ -32,6 +32,10 @@
   population indexing and lossless node reordering with subset.
   (:user:`petrelharp`, :pr:`1097`)
 
+**Breaking changes**
+
+- tskit now requires Python 3.6 (:user:`benjeffery`, :pr:`xxxx`)
+
 --------------------
 [0.3.4] - 2020-12-02
 --------------------

python/setup.py

@@ -77,14 +77,13 @@ def finalize_options(self):
     author="tskit developers",
     version=tskit_version,
     author_email="admin@tskit.dev",
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     classifiers=[
         "Development Status :: 4 - Beta",
         "Intended Audience :: Developers",
         "Topic :: Scientific/Engineering :: Bio-Informatics",
         "License :: OSI Approved :: MIT License",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",