There are six sequence types: strings, Unicode strings, lists, tuples, buffers, and xrange objects.
Strings literals are written in single or double quotes:
'xyzzy'
, "frobozz"
. See chapter 2 of the
Python Reference Manual for more about
string literals. Unicode strings are much like strings, but are
specified in the syntax using a preceeding "u" character:
u'abc'
, u"def"
. Lists are constructed with square brackets,
separating items with commas: [a, b, c]
. Tuples are
constructed by the comma operator (not within square brackets), with
or without enclosing parentheses, but an empty tuple must have the
enclosing parentheses, e.g., a, b, c
or ()
. A single
item tuple must have a trailing comma, e.g., (d,)
. Buffers are
not directly supported by Python syntax, but can be created by calling the
builtin function buffer(). XRanges
objects are similar to buffers in that there is no specific syntax to
create them, but they are created using the xrange()
function.
Sequence types support the following operations. The "in" and "not in" operations have the same priorities as the comparison operations. The "+" and "*" operations have the same priority as the corresponding numeric operations.^{2.4}
This table lists the sequence operations sorted in ascending priority (operations in the same box have the same priority). In the table, s and t are sequences of the same type; n, i and j are integers:
Operation  Result  Notes 

x in s 
1 if an item of s is equal to x, else 0 

x not in s 
0 if an item of s is
equal to x, else 1 

s + t 
the concatenation of s and t  
s * n , n * s 
n copies of s concatenated  (1) 
s[i] 
i'th item of s, origin 0  (2) 
s[i:j] 
slice of s from i to j  (2), (3) 
len(s) 
length of s  
min(s) 
smallest item of s  
max(s) 
largest item of s 
Notes:
0
are treated as
0
(which yields an empty sequence of the same type as
s).
len(s) + i
or
len(s) + j
is substituted. But note that 0
is
still 0
.
i <=
k < j
. If i or j is greater than
len(s)
, use len(s)
. If i is omitted,
use 0
. If j is omitted, use len(s)
. If
i is greater than or equal to j, the slice is empty.