Python tutorial python tuple

Python tuples

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, n); tup2 = (1, 2, 3, 4, 5); tup3 = "A", "B", "C", "D";

Create an empty tuple

Tup1 = ();

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

Tup1 = (50,);

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, 3); tup2 = (1, 2,, 4, 5, 6, 7);p rint "tup1[0]:", Tup1[0]print "Tup2[1:5]:", Tup2[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/pythontup1 = (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, $);p rint Tup;del tup;print "after deleting tup:" Print tup;

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

(' Physics ', ' Chemistry ', 1997, 2000) After deleting Tup:traceback (most recent call last):  File "test.py", line 9, in <module>    print tup; Nameerror:name ' tup ' 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

Describe

Len ((1, 2, 3)) 3 counts the number of elements

(1, 2, 3) + (4, 5, 6) (1, 2, 3, 4, 5, 6) Connect

[' 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 iterations

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

Describe

L[2] ' spam! ' reads a third element

L[-2] ' Spam ' reverse read; Read the second last element of the countdown

L[1:] [' Spam ', ' spam! '] intercept 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 above example allows the result:

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.

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