Natural Language Processing with Python

Sequences

So far, we have seen two kinds of sequence object: strings and lists. Another kind of sequence is called a tuple. Tuples are formed with the comma operator , and typically enclosed using parentheses. We’ve actually seen them in the previous chapters, and sometimes referred to them as “pairs,” since there were always two members. However, tuples can have any number of members. Like lists and strings, tuples can be indexed and sliced , and have a length .

>>> t = 'walk', 'fem', 3 
>>> t
('walk', 'fem', 3)
>>> t[0] 
'walk'
>>> t[1:] 
('fem', 3)
>>> len(t) 

Caution!

Tuples are constructed using the comma operator. Parentheses are a more general feature of Python syntax, designed for grouping. ...