Python in a Nutshell

Sequence Operations

Python supports a variety of operations that can be applied to sequence types, including strings, lists, and tuples.

Sequences in General

Sequences are containers with items accessible by indexing or slicing, as we’ll discuss shortly. The built-in len function takes a container as an argument and returns the number of items in the container. The built-in min and max functions take one argument, a non-empty sequence (or other iterable) whose items are comparable, and they return the smallest and largest items in the sequence, respectively. You can also call min and max with multiple arguments, in which case they return the smallest and largest arguments, respectively.

Coercion and conversions

There is no implicit coercion between different sequence types except that normal strings are coerced to Unicode strings if needed. Conversion to strings is covered in detail in Chapter 9. You can call the built-in tuple and list functions with a single argument (a sequence or other iterable) to get an instance of the type you’re calling, with the same items in the same order as in the argument.

Concatenation

You can concatenate sequences of the same type with the + operator. You can also multiply any sequence S by an integer n with the * operator. The result of S * n or n * S is the concatenation of n copies of S. If n is zero or less than zero, the result is an empty sequence of the same type as S.

Sequence membership

The x in S operator tests to see whether object ...