Little tad cleaner way to insert script before body.

Author: JulienPalard

build_docs.py

@@ -32,11 +32,12 @@
 """
 
 from bisect import bisect_left as bisect
+from contextlib import contextmanager, suppress
 import filecmp
 import logging
 import logging.handlers
 import os
-import pathlib
+from pathlib import Path
 import re
 from shlex import quote
 import shutil
@@ -157,7 +158,7 @@ def changed_files(left, right):
     changed = []
 
     def traverse(dircmp_result):
-        base = pathlib.Path(dircmp_result.left).relative_to(left)
+        base = Path(dircmp_result.left).relative_to(left)
         changed.extend(str(base / file) for file in dircmp_result.diff_files)
         for dircomp in dircmp_result.subdirs.values():
             traverse(dircomp)
@@ -255,38 +256,38 @@ def translation_branch(locale_repo, locale_clone_dir, needed_version):
     return locate_nearest_version(branches, needed_version)
 
 
+@contextmanager
+def edit(file):
+    """Context manager to edit a file "in place", use it as:
+    with edit("/etc/hosts") as i, o:
+        for line in i:
+            o.write(line.replace("localhoat", "localhost"))
+    """
+    temporary = file.with_name(file.name + ".tmp")
+    with suppress(OSError):
+        os.unlink(temporary)
+    with open(file) as input_file:
+        with open(temporary, "w") as output_file:
+            yield input_file, output_file
+    os.rename(temporary, file)
+
+
 def setup_switchers(html_root):
     """Setup cross-links between cpython versions:
     - Cross-link various languages in a language switcher
     - Cross-link various versions in a version switcher
     """
     shutil.copy("switchers.js", os.path.join(html_root, "_static"))
-    shell_out(
-        " ".join(
-            [
-                "sed",
-                "-i",
-                quote(
-                    r's#\(^ *\)</body>$#\1<script type="text/javascript" src="_static/switchers.js"></script>\n\0#'
-                ),
-                os.path.join(html_root, "*.html"),
-            ]
-        ),
-        shell=True,
-    )
-    shell_out(
-        " ".join(
-            [
-                "sed",
-                "-i",
-                quote(
-                    r's#\(^ *\)</body>$#\1<script type="text/javascript" src="../_static/switchers.js"></script>\n\0#'
-                ),
-                os.path.join(html_root, "*/*.html"),
-            ]
-        ),
-        shell=True,
-    )
+    for file in Path(html_root).glob("**/*.html"):
+        depth = len(file.relative_to(html_root).parts) - 1
+        script = f"""    <script type="text/javascript" src="{'../' * depth}_static/switchers.js"></script>\n"""
+        with edit(file) as (i, o):
+            for line in i:
+                if line == script:
+                    continue
+                if line == "  </body>\n":
+                    o.write(script)
+                o.write(line)
 
 
 def build_one(