Sequence Types

There are three sequence types: strings, lists and tuples. Strings literals are written in single quotes: 'xyzzy'. 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 (s and t are sequences of the same type; n, i and j are integers):

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Notes:

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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. But note that -0 is still 0.

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The slice of s from i to j is defined as the sequence of items with index k such that <#4999#>i ;SPMlt;= k ;SPMlt; j<#4999#>. 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.