12. Python tuples

PythonMeta-group

A python tuple is similar to a list, except that the elements of a tuple cannot be modified.

Tuples use parentheses, and the list uses square brackets.

Tuple creation is simple, just add elements in parentheses and separate them with commas.

The following example:

Tup1 = ('Physics','Chemistry',1997, -) tup2= (1,2,3,4,5) Tup3="a","b","C","D"

Create an empty tuple

Tup = ()

When you include only one element in a tuple, you need to add a comma after the element

Tup = (10,)

Tuples are similar to strings, and subscript indexes start at 0 and can be intercepted, combined, and so on.

accessing tuples

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

#!/usr/bin/python tup1 = (' Physics ', ' Chemistry ', 1997, $) tup2 = (1, 2, 3, 4, 5, 6, 7) print "tup1[0]:", Tup1[0]print "Tup2[1:5]:", Tup2[1:5]

Execution Result:

tup1[0]:  physicstup2[1:5]:  (2345 )

modifying tuples

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

#!/usr/bin/-*-coding:utf-8 -*-= (34.56= ('  ABC'xyz') # The following modifications to the tuple element operation are illegal. # tup1[0= tup1 + tup2print tup3

Execution Result:

(34.56, ' abc ', ' XYZ ')

Delete a tuple

element values in tuples are not allowed to be deleted, but we can use the DEL statement to delete an entire tuple, as in the following example:

#!/usr/bin/= ('physics'chemistry'1997  -  ""print Tup

When the above instance tuple is deleted, the output variable will have exception information, the output is as follows:

('physics'chemistry'1997) After deleting Tup:traceback (most recent call last):  "test.py"9   in <module> ' tup ' are not     Defined

Tuple operators

As with strings, you can use the + and * numbers to perform operations between tuples. This means that they can be combined and copied, and a new tuple is generated after the operation.

Python Expressions	Results	Description
Len ((1, 2, 3))	3	Count the number of elements
(1, 2, 3) + (4, 5, 6)	(1, 2, 3, 4, 5, 6)	Connection
(' hi! ',) * 4	(' hi! ', ' hi! ', ' hi! ', ' hi! ')	Copy
3 in (1, 2, 3)	True	Whether the element exists
For x in (1, 2, 3): Print x,	1 2 3	Iteration

Tuple index, intercept

Because tuples are also a sequence, we can access the elements at the specified location in the tuple, or we can intercept an element in the index as follows:

Meta-group:

L = (' spam ', ' spam ', ' spam! ')

Python Expressions	Results	Description
L[2]	' spam! '	Reading a third element
L[-2]	' Spam '	Read backwards, read the second-to-last element
L[1:]	(' Spam ', ' spam! ')	Intercepting elements

No close delimiter

Arbitrarily unsigned objects, separated by commas, are tuples by default, as in the following example:

#!/usr/bin/python print ' abc ', -4.24E93, 18+6.6j, ' xyz ' x, y = 1, 2print "Value of X, y:", X, y

Execution results

abc-4.24e+93 (18+6.6j) Xyzvalue of X, Y:1 2

Tuple built-in functions

The Python tuple contains the following built-in functions

Serial Number	Method and Description
1	CMP (Tuple1, Tuple2) Compares two tuples of elements.
2	Len (tuple) Counts the number of tuple elements.
3	Max (tuple) Returns the element's maximum value in a tuple.
4	MIN (tuple) Returns the element minimum value in a tuple.
5	Tuple (SEQ) Converts a list to a tuple.

12. Python tuples