Tuples

Tuples are similar to lists but are immutable, so they cannot be changed once they have been created. The operators (in, + and *) and built-in functions (len, max and min) work with them in the same way as with lists, as none of these functions change the original. The index and slice notations work in the same way to get elements or slices, but cannot be used to add, remove or replace elements. Also, there are only two tuple methods: count and index. An important purpose of tuples is to be used as keys for dictionaries. They are also more efficient to use when you don’t need a change facility.

1()
2(1,)
3(1, 2, 3, 5)
4(1, "2.", 3.0, ["4a", "4b"], (5.1,5.2))
Line 2

A tuple with one element requires a comma.

Line 4

A tuple, like a Liste, can contain a mixture of other types as elements, including any Numbers, Strings, Tuples, Lists, Dictionaries, Files and functions.

A list can be converted to a tuple using the built-in tuple function:

>>> x = [1, 2, 3, 5]
>>> tuple(x)
(1, 2, 3, 5)

Conversely, a tuple can be converted into a list using the built-in list function:

>>> x = (1, 2, 3, 4)
>>> list(x)
[1, 2, 3, 4]

The advantages of tuples over Lists are:

  • Tuples are faster than lists.

    If you want to define a constant set of values and just cycle through them, you should use a tuple instead of a list.

  • Tuples can not be modified and are therefore write-protected.

  • Tuples can be used as keys in Dictionaries and values in Sets.

Summary

data type

mutable

ordered

indexed

duplicates

tuple