Titlecasing a string with exceptions

Question

Is there a standard way in Python to titlecase a string (i.e. words start with uppercase characters, all remaining cased characters have lowercase) but leaving articles like and, in, and of lowercased?

Answer 1

There are a few problems with this. If you use split and join, some white space characters will be ignored. The built-in capitalize and title methods do not ignore white space.

>>> 'There     is a way'.title()
'There     Is A Way'

If a sentence starts with an article, you do not want the first word of a title in lowercase.

Keeping these in mind:

import re 
def title_except(s, exceptions):
    word_list = re.split(' ', s)       # re.split behaves as expected
    final = [word_list[0].capitalize()]
    for word in word_list[1:]:
        final.append(word if word in exceptions else word.capitalize())
    return " ".join(final)

articles = ['a', 'an', 'of', 'the', 'is']
print title_except('there is a    way', articles)
# There is a    Way
print title_except('a whim   of an elephant', articles)
# A Whim   of an Elephant

Answer 2

Use the titlecase.py module! Works only for English.

>>> from titlecase import titlecase
>>> titlecase('i am a foobar bazbar')
'I Am a Foobar Bazbar'

GitHub: https://github.com/ppannuto/python-titlecase

Answer 3

There are these methods:

>>> mytext = u'i am a foobar bazbar'
>>> print mytext.capitalize()
I am a foobar bazbar
>>> print mytext.title()
I Am A Foobar Bazbar

There's no lowercase article option. You'd have to code that yourself, probably by using a list of articles you want to lower.

Answer 4

Stuart Colville has made a Python port of a Perl script written by John Gruber to convert strings into title case but avoids capitalizing small words based on rules from the New York Times Manual of style, as well as catering for several special cases.

Some of the cleverness of these scripts:

• they capitalizes small words like if, in, of, on, etc., but will un-capitalize them if they’re erroneously capitalized in the input.

• the scripts assume that words with capitalized letters other than the first character are already correctly capitalized. This means they will leave a word like “iTunes” alone, rather than mangling it into “ITunes” or, worse, “Itunes”.

• they skip over any words with line dots; “example.com” and “del.icio.us” will remain lowercase.

• they have hard-coded hacks specifically to deal with odd cases, like “AT&T” and “Q&A”, both of which contain small words (at and a) which normally should be lowercase.

• The first and last word of the title are always capitalized, so input such as “Nothing to be afraid of” will be turned into “Nothing to Be Afraid Of”.

• A small word after a colon will be capitalized.

You can download it here.

Answer 5

capitalize (word)

This should do. I get it differently.

>>> mytext = u'i am a foobar bazbar'
>>> mytext.capitalize()
u'I am a foobar bazbar'
>>>

Ok as said in reply above, you have to make a custom capitalize:

mytext = u'i am a foobar bazbar'

def xcaptilize(word):
    skipList = ['a', 'an', 'the', 'am']
    if word not in skipList:
        return word.capitalize()
    return word

k = mytext.split(" ") 
l = map(xcaptilize, k)
print " ".join(l)   

This outputs

I am a Foobar Bazbar

Answer 6

Python 2.7's title method has a flaw in it.

value.title()

will return Carpenter'S Assistant when value is Carpenter's Assistant

The best solution is probably the one from @BioGeek using titlecase from Stuart Colville. Which is the same solution proposed by @Etienne.

Answer 7

 not_these = ['a','the', 'of']
thestring = 'the secret of a disappointed programmer'
print ' '.join(word
               if word in not_these
               else word.title()
               for word in thestring.capitalize().split(' '))
"""Output:
The Secret of a Disappointed Programmer
"""

The title starts with capitalized word and that does not match the article.

Answer 8

One-liner using list comprehension and the ternary operator

reslt = " ".join([word.title() if word not in "the a on in of an" else word for word in "Wow, a python one liner for titles".split(" ")])
print(reslt)

Breakdown:

for word in "Wow, a python one liner for titles".split(" ") Splits the string into an list and initiates a for loop (in the list comprehenstion)

word.title() if word not in "the a on in of an" else word uses native method title() to title case the string if it's not an article

" ".join joins the list elements with a seperator of (space)

Answer 9

One important case that is not being considered is acronyms (the python-titlecase solution can handle acronyms if you explicitly provide them as exceptions). I prefer instead to simply avoid down-casing. With this approach, acronyms that are already upper case remain in upper case. The following code is a modification of that originally provided by dheerosaur.

# This is an attempt to provide an alternative to ''.title() that works with 
# acronyms.
# There are several tricky cases to worry about in typical order of importance:
# 0. Upper case first letter of each word that is not an 'minor' word.
# 1. Always upper case first word.
# 2. Do not down case acronyms
# 3. Quotes
# 4. Hyphenated words: drive-in
# 5. Titles within titles: 2001 A Space Odyssey
# 6. Maintain leading spacing
# 7. Maintain given spacing: This is a test.  This is only a test.

# The following code addresses 0-3 & 7.  It was felt that addressing the others 
# would add considerable complexity.


def titlecase(
    s,
    exceptions = (
        'and', 'or', 'nor', 'but', 'a', 'an', 'and', 'the', 'as', 'at', 'by',
        'for', 'in', 'of', 'on', 'per', 'to'
    )
):
    words = s.strip().split(' ')
        # split on single space to maintain word spacing
        # remove leading and trailing spaces -- needed for first word casing

    def upper(s):
        if s:
            if s[0] in '‘“"‛‟' + "'":
                return s[0] + upper(s[1:])
            return s[0].upper() + s[1:]
        return ''

    # always capitalize the first word
    first = upper(words[0])

    return ' '.join([first] + [
        word if word.lower() in exceptions else upper(word)
        for word in words[1:]
    ])


cases = '''
    CDC warns about "aggressive" rats as coronavirus shuts down restaurants
    L.A. County opens churches, stores, pools, drive-in theaters
    UConn senior accused of killing two men was looking for young woman
    Giant asteroid that killed the dinosaurs slammed into Earth at ‘deadliest possible angle,’ study reveals
    Maintain given spacing: This is a test.  This is only a test.
'''.strip().splitlines()

for case in cases:
    print(titlecase(case))

When run, it produces the following:

CDC Warns About "Aggressive" Rats as Coronavirus Shuts Down Restaurants L.A. County Opens Churches, Stores, Pools, Drive-in Theaters
UConn Senior Accused of Killing Two Men Was Looking for Young Woman
Giant Asteroid That Killed the Dinosaurs Slammed Into Earth at ‘Deadliest Possible Angle,’ Study Reveals
Maintain Given Spacing: This Is a Test.  This Is Only a Test.