STY: Apply pre-commit (black, isort) + use snake_case variables (#832)

This change standardizes the code formatting quite a bit.
Having standardized formatting makes the code easier to read
and reduces the diff.

This includes:

* Applying the black auto-formatter (also in the docs)
* Applying isort for import sorting
* Making sure that files end with a newline

Additionally, in several places the property function call style was replaced by the decorator style

.github/ISSUE_TEMPLATE/bug-report.md

@@ -14,7 +14,7 @@ Replace this: What happened? What were you trying to achieve?
 Which environment were you using when you encountered the problem?
 
 ```python
-$ python -m platform 
+$ python -m platform
 # TODO: Your output goes here
 
 $ python -c "import PyPDF2;print(PyPDF2.__version__)"

.github/ISSUE_TEMPLATE/feature-request.md

@@ -16,5 +16,6 @@ How would your feature be used? (Remove this if it is not applicable.)
 
 ```python
 from PyPDF2 import PdfFileReader, PdfFileWriter
+
 ...  # your new feature in action!
-```
+```

.github/workflows/benchmark.yaml

@@ -45,4 +45,4 @@ jobs:
         alert-threshold: '200%'
         comment-on-alert: true
         fail-on-alert: true
-        alert-comment-cc-users: '@MartinThoma'
+        alert-comment-cc-users: '@MartinThoma'

.github/workflows/github-ci.yaml

@@ -112,4 +112,4 @@ jobs:
         uses: codecov/codecov-action@v2
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          files: ./coverage.xml
+          files: ./coverage.xml

.isort.cfg

@@ -4,3 +4,4 @@ indent='    '
 multi_line_output=3
 length_sort=0
 include_trailing_comma=True
+known_third_party = dataclasses,pytest,setuptools

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 # pre-commit run --all-files
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.2.0
+    rev: v4.1.0
     hooks:
     -   id: check-ast
     -   id: check-byte-order-marker
@@ -23,10 +23,18 @@ repos:
 #     rev: v0.942
 #     hooks:
 #     -   id: mypy
-# -   repo: https://github.com/psf/black
-#     rev: 22.3.0
-#     hooks:
-#     -   id: black
+-   repo: https://github.com/asottile/seed-isort-config
+    rev: v2.2.0
+    hooks:
+    -   id: seed-isort-config
+-   repo: https://github.com/pre-commit/mirrors-isort
+    rev: v5.10.1
+    hooks:
+    -   id: isort
+-   repo: https://github.com/psf/black
+    rev: 22.3.0
+    hooks:
+    -   id: black
 # -   repo: https://github.com/asottile/pyupgrade
 #     rev: v2.31.1
 #     hooks:

CHANGELOG

@@ -127,7 +127,7 @@ Bug fixes (BUG):
 
 Robustness improvements (ROBUST):
 
-- title sometimes None (#744) 
+- title sometimes None (#744)
 
 Documentation (DOC):
 
@@ -235,7 +235,7 @@ Patch release 1.27.3, 2022-04-10
 - BUG: Error in Chinese character encoding (#463)
 - BUG: Code duplication in Scripts/2-up.py
 - ROBUST: Guard 'obj.writeToStream' with 'if obj is not None'
-- ROBUST: Ignore a /Prev entry with the value 0 in the trailer 
+- ROBUST: Ignore a /Prev entry with the value 0 in the trailer
 - MAINT: Remove Sample_Code (#726)
 - TST: Close file handle in test_writer (#722)
 - TST: Fix test_get_images (#730)

PyPDF2/__init__.py

@@ -1,9 +1,9 @@
+from PyPDF2 import pdf
 from PyPDF2._version import __version__
 from PyPDF2.merger import PdfFileMerger
 from PyPDF2.pagerange import PageRange, parse_filename_page_ranges
 from PyPDF2.papersizes import PaperSize
 from PyPDF2.pdf import PdfFileReader, PdfFileWriter
-from PyPDF2 import pdf
 
 __all__ = [
     "__version__",