Python3 Tuple

Python tuples are similar to lists, except that the elements of a tuple cannot be modified.

Tuples use parentheses( ), lists use square brackets[ ]。

Creating a tuple is simple: just add elements in parentheses, separated by commas.

Create an empty tuple

tup1 = ()

When a tuple contains only one element, you need to add a comma after the element,, otherwise the parentheses will be treated as an operator:

Tuples are similar to strings in that indexing starts from 0, and they can be sliced, combined, etc.

Accessing Tuples

Tuples can use index numbers to access values in the tuple, as in the following example:

The output of the above example is:

tup1[0]:  Google
tup2[1:5]:  (2, 3, 4, 5)

Modifying Tuples

The element values in a tuple are not allowed to be modified, but we can concatenate and combine tuples, as in the following example:

The output of the above example is:

(12, 34.56, 'abc', 'xyz')

Deleting Tuples

The element values in a tuple are not allowed to be deleted, but we can use the del statement to delete the entire tuple, as in the following example:

After the tuple in the above example is deleted, outputting the variable will cause an exception message. The output is as follows:

删除后的元组 tup : 
Traceback (most recent call last):
  File "test.py", line 8, in <module>
    print (tup)
NameError: name 'tup' is not defined

Tuple Operators

Like strings, tuples can use the+、+=and*+ sign for operations. This means they can be combined and copied, and a new tuple will be generated after the operation.

len((1, 2, 3))

>>> a = (1, 2, 3)
>>> b = (4, 5, 6)
>>> c = a+b
>>> c
(1, 2, 3, 4, 5, 6)

>>> a = (1, 2, 3)
>>> b = (4, 5, 6)
>>> a += b
>>> a
(1, 2, 3, 4, 5, 6)

('Hi!',) * 4

3 in (1, 2, 3)

for x in (1, 2, 3): 
    print (x, end=" ")

Tuple Indexing and Slicing

Because a tuple is also a sequence, we can access elements at specified positions in the tuple, and also slice a range of elements from indices, as shown below:

Tuple:

tup = ('Google', 'Example', 'Taobao', 'Wiki', 'Weibo','Weixin')

A running example is as follows:

Tuple Built-in Functions

Python tuples include the following built-in functions

>>> tuple1 = ('Google', 'Example', 'Taobao')
>>> len(tuple1)
3
>>> 

>>> tuple2 = ('5', '4', '8')
>>> max(tuple2)
'8'
>>> 

>>> tuple2 = ('5', '4', '8')
>>> min(tuple2)
'4'
>>> 

>>> list1= ['Google', 'Taobao', 'Example', 'Baidu']
>>> tuple1=tuple(list1)
>>> tuple1
('Google', 'Taobao', 'Example', 'Baidu')

About Tuples Being Immutable

The so-called immutability of a tuple means that the content in memory pointed to by the tuple is immutable.

From the above example, it can be seen that the reassigned tuple tup is bound to a new object, not modifying the original object.