DEP: Drop Python 3.6 support (#2369)

This does not mean that pypdf doesn't run with Python 3.6 anymore.
It means that we don't run CI with Python 3.6 and don't give any
guarantees.

See #2005

.github/workflows/github-ci.yaml

@@ -58,7 +58,7 @@ jobs:
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         use-crypto-lib: ["cryptography"]
         include:
-          - python-version: "3.6"
+          - python-version: "3.7"
             use-crypto-lib: "pycryptodome"
           - python-version: "3.7"
             use-crypto-lib: "none"
@@ -81,7 +81,7 @@ jobs:
         key: cache-downloaded-files
     - name: Setup Python
       uses: actions/setup-python@v5
-      if: matrix.python-version == '3.6' || matrix.python-version == '3.7' || matrix.python-version == '3.8' || matrix.python-version == '3.9' || matrix.python-version == '3.10'
+      if: matrix.python-version == '3.7' || matrix.python-version == '3.8' || matrix.python-version == '3.9' || matrix.python-version == '3.10'
       with:
         python-version: ${{ matrix.python-version }}
         cache: 'pip'
@@ -100,7 +100,7 @@ jobs:
     - name: Install requirements (Python 3)
       run: |
         pip install -r requirements/ci.txt
-      if: matrix.python-version == '3.6' || matrix.python-version == '3.7' || matrix.python-version == '3.8' || matrix.python-version == '3.9' || matrix.python-version == '3.10'
+      if: matrix.python-version == '3.7' || matrix.python-version == '3.8' || matrix.python-version == '3.9' || matrix.python-version == '3.10'
     - name: Install requirements (Python 3.11+)
       run: |
         pip install -r requirements/ci-3.11.txt

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 # pre-commit run --all-files
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.5.0
+    rev: v4.1.0
     hooks:
     -   id: check-ast
     -   id: check-byte-order-marker
@@ -18,34 +18,34 @@ repos:
     -   id: check-added-large-files
         args: ['--maxkb=1000']
 -   repo: https://github.com/psf/black
-    rev: 23.10.1
+    rev: 23.3.0
     hooks:
     -   id: black
-        args: [--target-version, py36]
+        args: [--target-version, py37]
 -   repo: https://github.com/asottile/blacken-docs
-    rev: 1.16.0
+    rev: 1.14.0
     hooks:
     -   id: blacken-docs
         additional_dependencies: [black==22.1.0]
         exclude: "docs/user/robustness.md"
 -   repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.1.3
+    rev: v0.1.9
     hooks:
     -   id: ruff
         args: ['--fix']
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v3.15.0
+    rev: v3.3.2
     hooks:
     -   id: pyupgrade
-        args: [--py36-plus]
+        args: [--py37-plus]
 -   repo: https://github.com/pycqa/flake8
-    rev: 6.1.0
+    rev: 5.0.4
     hooks:
     -   id: flake8
         args: ["--ignore", "E,W,F"]
 
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v1.6.1'
+    rev: 'v1.4.0'
     hooks:
       - id: mypy
         additional_dependencies: [types-Pillow==10.0.0.2]

.pylintrc

@@ -53,7 +53,7 @@ persistent=yes
 
 # Minimum Python version to use for version dependent checks. Will default to
 # the version used to run pylint.
-py-version=3.6
+py-version=3.7
 
 # Discover python modules and packages in the file system subtree.
 recursive=no

Makefile

@@ -1,10 +1,8 @@
 maint:
-	pyenv local 3.6.15
+	pyenv local 3.7.15
 	pre-commit autoupdate
 	pip-compile -U requirements/ci.in
-	pyenv local 3.7.15
 	pip-compile -U requirements/dev.in
-	pyenv local 3.7.9
 	pip-compile -U requirements/docs.in
 
 release:

docs/dev/testing.md

@@ -28,8 +28,7 @@ so that you can install the different Python versions:
 
 ```
 pyenv install pypy3.8-7.3.7
-pyenv install 3.6.15
-pyenv install 3.7.12
+pyenv install 3.7.15
 pyenv install 3.8.12
 pyenv install 3.9.10
 pyenv install 3.10.2

docs/user/encryption-decryption.md

@@ -6,8 +6,8 @@ with different key length. `pypdf` supports all of them until `PDF-2.0`, which
 is the latest PDF standard.
 
 `pypdf` use an extra dependency to do encryption or decryption for `AES` algorithms.
-We recommend [`pyca/cryptography`](https://cryptography.io/en/latest/). For Python 3.6
-users, you can use [`pycryptodome`](https://pypi.org/project/pycryptodome/) as a fallback.
+We recommend [`pyca/cryptography`](https://cryptography.io/en/latest/). Alternatively,
+you can use [`pycryptodome`](https://pypi.org/project/pycryptodome/).
 
 > Please see the note in the [installation guide](installation.md)
 > for installing the extra dependencies if interacting with PDFs that use AES.

docs/user/installation.md

@@ -4,7 +4,7 @@ There are several ways to install pypdf. The most common option is to use pip.
 
 ## pip
 
-pypdf requires Python 3.6+ to run.
+pypdf requires Python 3.7+ to run.
 
 Typically Python comes with `pip`, a package installer. Using it you can
 install pypdf:
@@ -52,6 +52,7 @@ pip install pypdf[image]
 
 | Python                 | 3.11 | 3.10 | 3.9 | 3.8 | 3.7 | 3.6 | 2.7 |
 | ---------------------- | ---- | ---- | --- | --- | --- | --- | --- |
+| pypdf>=4.0             | YES  | YES  | YES | YES | YES |     |     |
 | pypdf>=3.0             | YES  | YES  | YES | YES | YES | YES |     |
 | PyPDF2>=2.0            | YES  | YES  | YES | YES | YES | YES |     |
 | PyPDF2 1.20.0 - 1.28.4 |      | YES  | YES | YES | YES | YES | YES |

pypdf/_xobj_image_helpers.py

@@ -20,7 +20,7 @@
 else:
     # PEP 586 introduced typing.Literal with Python 3.8
     # For older Python versions, the backport typing_extensions is necessary:
-    from typing_extensions import Literal  # type: ignore[assignment]
+    from typing_extensions import Literal
 
 if sys.version_info[:2] >= (3, 10):
     from typing import TypeAlias

pypdf/types.py

@@ -7,7 +7,7 @@
     # Python 3.8+: https://peps.python.org/pep-0586
     from typing import Literal
 else:
-    from typing_extensions import Literal  # type: ignore[assignment]
+    from typing_extensions import Literal
 
 if sys.version_info[:2] >= (3, 10):
     # Python 3.10+: https://www.python.org/dev/peps/pep-0484/

pyproject.toml

@@ -17,7 +17,6 @@ classifiers = [
     "License :: OSI Approved :: BSD License",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",

requirements/ci.txt

@@ -1,57 +1,56 @@
 #
-# This file is autogenerated by pip-compile with python 3.6
+# This file is autogenerated by pip-compile with python 3.7
 # To update, run:
 #
 #    pip-compile requirements/ci.in
 #
-attrs==20.3.0
-    # via
-    #   flake8-bugbear
-    #   flake8-implicit-str-concat
-    #   pytest
-coverage[toml]==6.2
+attrs==23.1.0
+    # via flake8-bugbear
+coverage[toml]==7.2.7
     # via
     #   -r requirements/ci.in
     #   pytest-cov
-execnet==1.9.0
+exceptiongroup==1.2.0
+    # via pytest
+execnet==2.0.2
     # via pytest-xdist
 flake8==5.0.4
     # via
     #   -r requirements/ci.in
     #   flake8-bugbear
     #   flake8-print
-flake8-bugbear==22.9.23
+flake8-bugbear==23.3.12
     # via -r requirements/ci.in
-flake8-implicit-str-concat==0.2.0
+flake8-implicit-str-concat==0.4.0
     # via -r requirements/ci.in
-flake8-print==4.0.1
+flake8-print==5.0.0
     # via -r requirements/ci.in
 fpdf2==2.4.1
     # via -r requirements/ci.in
 importlib-metadata==4.2.0
     # via
+    #   attrs
     #   flake8
     #   pluggy
     #   pytest
-iniconfig==1.1.1
+    #   typeguard
+iniconfig==2.0.0
     # via pytest
 mccabe==0.7.0
     # via flake8
-more-itertools==8.14.0
+more-itertools==9.1.0
     # via flake8-implicit-str-concat
-mypy==0.971
+mypy==1.4.1
     # via -r requirements/ci.in
 mypy-extensions==1.0.0
     # via mypy
-packaging==21.3
+packaging==23.2
     # via pytest
-pillow==8.4.0
+pillow==9.5.0
     # via
     #   -r requirements/ci.in
     #   fpdf2
-pluggy==1.0.0
-    # via pytest
-py==1.11.0
+pluggy==1.2.0
     # via pytest
 py-cpuinfo==9.0.0
     # via pytest-benchmark
@@ -63,46 +62,43 @@ pycryptodome==3.19.0
     # via -r requirements/ci.in
 pyflakes==2.5.0
     # via flake8
-pyparsing==3.1.1
-    # via packaging
-pytest==7.0.1
+pytest==7.4.3
     # via
     #   -r requirements/ci.in
     #   pytest-benchmark
     #   pytest-cov
     #   pytest-socket
     #   pytest-timeout
     #   pytest-xdist
-pytest-benchmark==3.4.1
+pytest-benchmark==4.0.0
     # via -r requirements/ci.in
-pytest-cov==4.0.0
+pytest-cov==4.1.0
     # via -r requirements/ci.in
-pytest-socket==0.4.1
+pytest-socket==0.6.0
     # via -r requirements/ci.in
-pytest-timeout==2.1.0
+pytest-timeout==2.2.0
     # via -r requirements/ci.in
-pytest-xdist==3.0.2
+pytest-xdist==3.5.0
     # via -r requirements/ci.in
 pyyaml==6.0.1
     # via -r requirements/ci.in
-six==1.16.0
-    # via flake8-print
-tomli==1.2.3
+tomli==2.0.1
     # via
     #   coverage
     #   mypy
     #   pytest
 typed-ast==1.5.5
     # via mypy
-typeguard==2.13.3
+typeguard==4.1.2
     # via -r requirements/ci.in
 types-dataclasses==0.6.6
     # via -r requirements/ci.in
-types-pillow==10.0.0.3
+types-pillow==10.1.0.2
     # via -r requirements/ci.in
-typing-extensions==4.1.1
+typing-extensions==4.7.1
     # via
     #   importlib-metadata
     #   mypy
-zipp==3.6.0
+    #   typeguard
+zipp==3.15.0
     # via importlib-metadata

requirements/dev.txt

@@ -8,23 +8,23 @@ black==23.3.0
     # via -r requirements/dev.in
 build==1.0.3
     # via pip-tools
-certifi==2023.7.22
+certifi==2023.11.17
     # via requests
 cfgv==3.3.1
     # via pre-commit
-charset-normalizer==3.3.1
+charset-normalizer==3.3.2
     # via requests
 click==8.1.7
     # via
     #   black
     #   pip-tools
 coverage[toml]==7.2.7
     # via pytest-cov
-distlib==0.3.7
+distlib==0.3.8
     # via virtualenv
 docutils==0.20.1
     # via flit
-exceptiongroup==1.1.3
+exceptiongroup==1.2.0
     # via pytest
 filelock==3.12.2
     # via virtualenv
@@ -34,7 +34,7 @@ flit-core==3.9.0
     # via flit
 identify==2.5.24
     # via pre-commit
-idna==3.4
+idna==3.6
     # via requests
 importlib-metadata==6.7.0
     # via
@@ -60,7 +60,7 @@ pillow==9.5.0
     # via -r requirements/dev.in
 pip-tools==6.14.0
     # via -r requirements/dev.in
-platformdirs==3.11.0
+platformdirs==4.0.0
     # via
     #   black
     #   virtualenv
@@ -98,9 +98,9 @@ typing-extensions==4.7.1
     #   platformdirs
 urllib3==2.0.7
     # via requests
-virtualenv==20.24.6
+virtualenv==20.25.0
     # via pre-commit
-wheel==0.41.2
+wheel==0.42.0
     # via
     #   -r requirements/dev.in
     #   pip-tools

requirements/docs.in

@@ -1,4 +1,4 @@
 sphinx
-sphinx_rtd_theme
+sphinx_rtd_theme<2.0.0
 myst_parser==0.16.1
 attrs  # required for myst, but not automatically installed by myst