There are three standard sequence operations (+
,
*
, []
) that can be performed with
tuple
s as well as list
s
and string
s.
The +
operator creates a new
tuple
as the concatenation of the arguments.
Here's an example.
>>>
("chapter",8) + ("strings","tuples","lists")
('chapter', 8, 'strings', 'tuples', 'lists')
The *
operator between tuple
s
and numbers (number *
tuple
or
tuple
*
number) creates a new
tuple
that is a number of repetitions of the
input tuple
.
>>>
2*(3,"blind","mice")
(3, 'blind', 'mice', 3, 'blind', 'mice')
The []
operator selects an item or a slice from the
tuple
. There are two forms. The first format is
tuple
[
index
]
. Items are numbered from 0
at beginning through the length. They are also number from -1 at the end
backwards to
-len
(
tuple
).
The slice format is
tuple
[
start
:
end
]
. Elements from
start
to
end
-1 are chosen; there will be
end
−
start
elements in the
resulting tuple
. If
start
is omitted, it is the beginning of the
tuple
(position 0), if
end
is omitted, it is the end of the tuple
(position -1).
>>>
t=( (2,3), (2,"hi"), (3,"mom"), 2+3j, 6.02E23 )
>>>
t[2]
(3, 'mom')
>>>
print t[:3], 'and', t[3:]
((2, 3), (2, 'hi'), (3, 'mom')) and ((2+3j), 6.02e+23)
>>>
print t[-1], 'then', t[-3:]
6.02e+23 then ((3, 'mom'), (2+3j), 6.02e+23)