Sequence Types

There are three sequence types: strings , lists, and tuples . String literals are written in single or double quotes: 'xyzzy', "frobozz". See Chapter 2 of the Python reference manual for more about string literals. 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,).

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]

The following table lists the sequence operations sorted in ascending priority (operations in the same box have the same priority). s and t are sequences of the same type; n, i, and j are integers.




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



i‘th item of s, origin 0



Slice of s from i to j

1, 2


Length of s



Smallest item of s



Largest item of s



  1. If i or j is negative, the index is relative to the end of the string; i.e., len(s) + i or len(s) + j is substituted. ...

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