Question

Of the istitle() string method, the Python 2.6.5 manual reads:

Return true if the string is a titlecased string and there is at least one character, for example uppercase characters may only follow uncased characters and lowercase characters only cased ones. Return false otherwise.

But in this case it returns false:

>>> book = 'what every programmer must know'
>>> book.title()
'What Every Programmer Must Know'
>>> book.istitle()
False

What am I missing?

Answer 1

The method title() doesn’t mutate the string (strings are immutable in Python). It creates a new string which you must assign to your variable:

>>> book = 'what every programmer must know'
>>> book = book.title()
>>> book.istitle()
True