Python Tuples


Contents

When Python objects are considered, Tuples found to be available in a sequence of immutable. As mentioned, Tuples are sequences, which can be described as lists. If confused between list and Tuples, then understand that users can alter the lists. Whereas, Tuples cannot be changed as it applies parentheses, whereas lists use square brackets.

Developing Tuples require putting different comma-separated values. Usually, users can insert these comma-separated values between parentheses as well. For example :

tup1 = ('physics', 'chemistry', 1997, 2000);
tup2 = (1, 2, 3, 4, 5 );
tup3 = "a", "b", "c", "d";

The empty tuple is written as two parentheses containing nothing :

tup1 = ();

To write a tuple containing a single value you have to include a comma, even though there is only one value :

tup1 = (50,);

Like string indices, tuple indices start at 0, and they can be sliced, concatenated, and so on.

Accessing Values in Tuples

To access values in tuple, use the square brackets for slicing along with the index or indices to obtain value available at that index. For example :

#!/usr/bin/python

tup1 = ('physics', 'chemistry', 1997, 2000);
tup2 = (1, 2, 3, 4, 5, 6, 7 );
print "tup1[0]: ", tup1[0];
print "tup2[1:5]: ", tup2[1:5];

When the above code is executed, it produces the following result :

tup1[0]:  physics
tup2[1:5]:  [2, 3, 4, 5]

Updating Tuples

Tuples are immutable. There could be any modification escapes available in Tuples. Users cannot update or change the values of the elements. Users can use the portions of accessible tuples to develop new tuples as the following example demonstrates :

#!/usr/bin/python

tup1 = (12, 34.56);
tup2 = ('abc', 'xyz');

# Following action is not valid for tuples
# tup1[0] = 100;

# So let's create a new tuple as follows
tup3 = tup1 + tup2;
print tup3;

When the above code is executed, it produces the following result :

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

Delete Tuple Elements

Eliminating single Tuple is beyond the programming capacities. The solution that exists if some Tuple is required elimination, then putting together another Tuple with the undesired elements discarded could resolve the issue. 

To explicitly remove an entire tuple, just use the del statement. For example :

#!/usr/bin/python

tup = ('physics', 'chemistry', 1997, 2000);
print tup;
del tup;
print "After deleting tup : ";
print tup;

This produces the following result. Note an exception raised, this is because after del tup tuple does not exist any more :

('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

Basic Tuples Operations

Tuples respond to the + and * operators much like strings; they mean concatenation and repetition here too, except that the result is a new tuple, not a string.

In fact, tuples respond to all of the general sequence operations we used on strings in the prior chapter :

Python Expression

Results

Description

len((1, 2, 3))

3

Length

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

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

Concatenation

('Hi!',) * 4

('Hi!', 'Hi!', 'Hi!', 'Hi!')

Repetition

3 in (1, 2, 3)

True

Membership

for x in (1, 2, 3): print x,

1 2 3

Iteration

Indexing, Slicing, and Matrixes

Because tuples are sequences, indexing and slicing work the same way for tuples as they do for strings. Assuming following input :

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

Python Expression

Results

Description

<'SPAM!'

<'Spam'

<['Spam', 'SPAM!']

No Enclosing Delimiters

#!/usr/bin/python

print 'abc', -4.24e93, 18+6.6j, 'xyz';
x, y = 1, 2;
print "Value of x , y : ", x,y;

When the above code is executed, it produces the following result :

abc -4.24e+93 (18+6.6j) xyz
Value of x , y : 1 2

Built-in Tuple Functions

Python includes the following tuple functions :

Sr.No.

Function with Description

1

cmp(tuple1, tuple2)

Compares elements of both tuples.

2

len(tuple)

Gives the total length of the tuple.

3

max(tuple)

Returns item from the tuple with max value.

4

min(tuple)

Returns item from the tuple with min value.

5

tuple(seq)

Converts a list into tuple.

Here at Intellinuts, we have created a complete Python tutorial for Beginners to get started in Python.



Navigation
Tutorial
Tutorial
Tutorial