Python Automation 3.0-------Learning path--------tuples!

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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, 2000); =  (1 2, 3 , 4,  5 =  "a" , "B" ,  "C"   "D"          

Create an empty tuple

=();

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

=(a);  

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/pythonTup1= (' Physics ', ' Chemistry ', 1997, 2000);Tup2= (1, 2, 3,  4, 5,6, 7print  "tup1[0": ",< Span class= "PLN" > Tup1[0] print  "Tup2[1:5": ",[1:5]    

The result of the above example output:

Tup1[0]:  physicstup2[1:5]:(2,3,4, 5)                 

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/python#-*-Coding:utf-8-*-tup1 = ( 34.56);  Tup2 = (' abc ', ' xyz ');  # The following modification of tuple element operations is illegal. # Tup1[0] = 100; # Create a new tuple tup3 = tup1 + tup2;  Print tup3;                

The result of the above example output:

(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/pythontup  =  ( ' physics ' ,  ' chemistry ' , 1997,< Span class= "PLN" > 2000print Tup;del Tup;print  "after deleting tup:"  Tup           

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

(' Physics ', ' Chemistry ', 1997, 2000)Afterdeleting Tup:traceback  ( Most recent call last):  file   "test.py" , line 9, in <module>  print Tup;nameerror: name  ' tup '  Span class= "KWD" >is 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:

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

Python Expressions	Results	Description
L[2]	' spam! '	Reading a third element
L[-2]	' Spam '	Read the second last element of the inverse
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/pythonprint  ' abc '  -4.24e93,  18+6.6j,  ' XYZ ' x, y =1, 2; print  "Value of X, y:" , x ,y          

The result of the above example operation:

-4.24e+93(+6.6j) xyzValue,:12    

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.

Python Automation 3.0-------Learning path--------tuples!