[chaley]

Originally Posted by Karellen

I think there is a bug in Calibre when using these change case functions. The entire text block you want to change needs to have a uniform case. No mixed cases as in your example.

Its behavior is intentional. The function considers uppercase words to be uppercased intentionally, as in "He was at the MOD" , "The FBI is on the case", or "She lives in CA".

Here is the source for calibre's titlecase() function.

def titlecase(text):
    """
    Titlecases input text

    This filter changes all words to Title Caps, and attempts to be clever
    about *un*capitalizing SMALL words like a/an/the in the input.

    The list of "SMALL words" which are not capped comes from
    the New York Times Manual of Style, plus 'vs' and 'v'.

    """

    all_caps = icu_upper(text) == text

    pat = re.compile(r'(\s+)')
    line = []
    for word in pat.split(text):
        if not word:
            continue
        if pat.match(word) is not None:
            line.append(word)
            continue
        if all_caps:
            if UC_INITIALS.match(word):
                line.append(word)
                continue
            else:
                word = icu_lower(word)

        if APOS_SECOND.match(word):
            word = word.replace(word[0], icu_upper(word[0]), 1)
            word = word[:2] + icu_upper(word[2]) + word[3:]
            line.append(word)
            continue
        if INLINE_PERIOD.search(word) or UC_ELSEWHERE.match(word):
            line.append(word)
            continue
        if SMALL_WORDS.match(word):
            line.append(icu_lower(word))
            continue

        hyphenated = []
        for item in word.split('-'):
            hyphenated.append(CAPFIRST.sub(lambda m: icu_upper(m.group(0)), item))
        line.append("-".join(hyphenated))

    result = "".join(line)

    result = SMALL_FIRST.sub(lambda m: '{}{}'.format(
        m.group(1),
        capitalize(m.group(2))
    ), result)

    result = SMALL_AFTER_NUM.sub(lambda m: '{}{}'.format(m.group(1),
        capitalize(m.group(2))
    ), result)

    result = SMALL_LAST.sub(lambda m: capitalize(m.group(0)), result)

    result = SUBPHRASE.sub(lambda m: '{}{}'.format(
        m.group(1),
        capitalize(m.group(2))
    ), result)

    return result