DEV: Improve CHANGELOG generation

Makefile

@@ -4,6 +4,9 @@ maint:
 	pip-compile -U requirements/dev.in
 	pip-compile -U requirements/docs.in
 
+changelog:
+	python make_changelog.py
+
 upload:
 	make clean
 	python setup.py sdist bdist_wheel && twine upload -s dist/*

make_changelog.py

@@ -24,7 +24,7 @@ def main(changelog_path: str):
     today = datetime.now()
     header = f"Version {new_version}, {today:%Y-%m-%d}\n"
     header = header + "-" * (len(header) - 1) + "\n"
-    trailer = f"Full Changelog: https://github.com/py-pdf/PyPDF2/compare/{git_tag}...{new_version}"
+    trailer = f"\nFull Changelog: https://github.com/py-pdf/PyPDF2/compare/{git_tag}...{new_version}\n\n"
     new_entry = header + changes + trailer
     print(new_entry)
 
@@ -107,15 +107,23 @@ def get_most_recent_git_tag():
 def get_git_commits_since_tag(git_tag) -> List[Change]:
     commits = str(
         subprocess.check_output(
-            ["git", "--no-pager", "log", f"{git_tag}..HEAD", "--oneline"],
+            [
+                "git",
+                "--no-pager",
+                "log",
+                f"{git_tag}..HEAD",
+                '--pretty=format:"%h%x09%s"',
+            ],
             stderr=subprocess.STDOUT,
         )
     ).strip("'b\\n")
     return [parse_commit_line(line) for line in commits.split("\\n")]
 
 
 def parse_commit_line(line) -> Change:
-    commit_hash, rest = line[: len("d5a5eea")], line[len("d5a5eea") :]
+    if "\\t" not in line:
+        raise ValueError(f"Invalid commit line: {line}")
+    commit_hash, rest = line.split("\\t", 1)
     if ":" in rest:
         prefix, message = rest.split(":", 1)
     else: