WIP: mostly scratch code still

src/pycalver/rewrite.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+# This file is part of the pycalver project
+# https://github.com/mbarkhau/pycalver
+#
+# (C) 2018 Manuel Barkhau (@mbarkhau)
+# SPDX-License-Identifier: MIT
+
+import logging
+import difflib
+
+log = logging.getLogger("pycalver.rewrite")
+
+
+def rewrite_file(file: str, pattern: str, dry=False) -> None:
+    difflib.unified_diff(
+        file_content_before.splitlines(),
+        file_content_after.splitlines(),
+        lineterm="",
+        fromfile="a/" + file,
+        tofile="b/" + file,
+    )