Capitalise title

biblio.py

# Original by Daniel L. Greenwald
# http://dlgreenwald.weebly.com/blog/capitalizing-titles-in-bibtex
# Modified by Garrett Dash Nelson

import re
from titlecase import titlecase

def capitalise(x):
  if x[0].isupper():
    x = "{" + x[0] + "}" + x[1:]
  return x

# Input and output files
my_file = 'References.bib'
new_file = 'ReferencesCapitalized.bib' # in case you don't want to overwrite

# Match title, Title, booktitle, Booktitle fields
pattern = re.compile(r'(\W*)(title|journal)\s*=\s*{(.*)},')

# Read in old file
with open(my_file, 'r') as fid:
    lines = fid.readlines()

# Search for title strings and replace with titlecase
newlines = []
errors = []
for line in lines:
    # Check if line contains title
    match_obj = pattern.match(line)

    if match_obj is not None:
        # Need to "escape" any special chars to avoid misinterpreting them in the regular expression.
        oldtitle = re.escape(match_obj.group(3))

        # Apply titlecase to get the correct title.
        newtitle = titlecase(match_obj.group(3))

        # Replace and add to list
        p_title = re.compile(oldtitle)
        try:
          # Map is a lazy operation in Python 3
          result = map(capitalise, newtitle.split(" "))
          # Force lazy evaluation with list(...)
          newtitle = " ".join(list(result))

          newline = p_title.sub(newtitle, line)
        except Exception as e:
          errors.append((e, newtitle))
        finally:
          newlines.append(newline)
    else:
      # if not title, add as is.
      newlines.append(line)


# Print output to new file
with open (new_file, 'w') as fid:
    fid.writelines(newlines)

if errors:
   print("This is an exception, please check the following articles:")
   for (e, title) in errors:
     print(f"f{e} -- {title}")