add an end adder script

Akuli · Akuli · commit 93c02c20b6b3 · 2016-11-30T17:59:44.000+02:00
diff --git a/update-ends.py b/update-ends.py
@@ -0,0 +1,102 @@
+"""Update ends of markdown files."""
+
+import collections
+import glob
+import re
+
+
+BASIC_END = """
+***
+
+You may use this tutorial freely at your own risk. See
+[LICENSE](LICENSE).
+"""
+
+CHAPTER_END = BASIC_END + """
+[Previous]({prev}) | [Next]({next}) |
+[Back to the list of contents](README.md#list-of-contents)
+"""
+
+MARKDOWN_LINK_REGEX = r'\[.*\]\((.*\.md)\)'
+CHAPTER_LINK_REGEX = '^\d+\. ' + MARKDOWN_LINK_REGEX + '$'
+
+
+def get_filenames():
+    """Get chapter files and other files from README.
+
+    Return a two-tuple of chapter files and other files.
+    """
+    chapters = []
+    with open('README.md', 'r') as f:
+        # move to where the content list starts
+        while f.readline().strip() != "## List of contents":
+            pass
+
+        # now let's read the content list
+        for line in f:
+            line = line.strip()
+            if line:
+                # not empty line
+                match = re.search(CHAPTER_LINK_REGEX, line)
+                if match is None:
+                    # end of content list
+                    break
+                chapters.append(match.group(1))
+
+    # now let's find other links to markdown files
+    with open('README.md', 'r') as f:
+        all_files = re.findall(MARKDOWN_LINK_REGEX, f.read())
+    others = set(all_files) - set(chapters)
+
+    return chapters, others
+
+
+def has_end(filename, template):
+    linecount = template.count('\n')
+    with open(filename, 'r') as f:
+        # get the last linecount lines
+        filelines = collections.deque(f, maxlen=linecount)
+    templatelines = template.rstrip('\n').split('\n')
+
+    for templateline, fileline in zip(templatelines, filelines):
+        if '{' not in templateline:
+            # It doesn't contain formatting, we can do something with it.
+            if templateline.strip() != fileline.strip():
+                # It's different than what using the template would result in.
+                return False
+
+    # All lines matched if we get here.
+    return True
+
+
+def main():
+    chapter_files, other_files = get_filenames()
+
+    # make previous of first file and next of last file to just bring
+    # back to README
+    prevs = ['README.md'] + chapter_files[:-1]
+    nexts = chapter_files[1:] + ['README.md']
+
+    print("Chapter files")
+    for filename, prev, next in zip(chapter_files, prevs, nexts):
+        if has_end(filename, CHAPTER_END):
+            print("  Has end:", filename)
+        else:
+            print("  Adding end:", filename)
+            with open(filename, 'a') as f:
+                f.write(CHAPTER_END.format(prev=prev, next=next))
+
+    print()
+
+    print("Other files")
+    for filename in other_files:
+        if has_end(filename, BASIC_END):
+            print("  Has end:", filename)
+        else:
+            print("  Adding end:", filename)
+            with open(filename, 'a') as f:
+                f.write(BASIC_END)
+
+
+if __name__ == '__main__':
+    main()
