Tuples

Tuples     AU : May-19, Dec.-19, Marks 16

Tuple is a sequence of values. It is similar to list but there lies difference between tuple and list

Difference between Tuple and List

Tuple

1. Tuple use parenthesis

2. Tuples can not be change

List

1. List use square brackets

2. Lists can be changed.

Tuple is said to immutable. That means once created we can not change the tuple.

Examples of tuples

T1 = (10,20,30,40)

T2 = (-a', 'b','c','d')

T3 = (‘A’,10,20)

T4 = ('aaa','bbb’,30,40)

The empty tuple can be created as

T1 = ( )

How to Write Tuple ?

Tuple is written within the parenthesis. Even if the tuple contains a single value, the comma is used as a separator. For example -

T1 = (10)

The tuple index starts at 0. For example

>>> t1 = (10,20, 'AAA','BBB')

>>> print(t1[0])

10 >>> print(t1[1:31)

(20, 'AAA')

>>> 

 

1. Tuple Assignment

• We can create a tuple by using assignment operator. Multiple assignments are possible at a time using tuple assignment. For example –

>>> a,b=10,20

>>> print(a)

10

>>> print(b)

20

>>>

• Here the left side is a tuple of variables; the right side is a tuple of expressions.

• Each value is assigned to its respective variable.

• All the expressions on the right side are evaluated before any of the assignments.

• Note that the number of variables on the left and right have to be the same.

• We can also separate out the values in the expression in the tuple by using the split function. For example

>>> student = 'AAA, 123'

>>> name,roll = student.split(',').

>>> print(name)

AAA

>>> print(roll)

123

>>>

• In above example, the expression is split at comma and the two separated values are collected in two different variables. We have name and roll variables in which the corresponding values are stored.

 

2. Tuple as Return Value

Normally function return a single value, but if the value is tuple, then multiple values can be returned.

For example -

Test.py

def student_Info():

name='AAA

roll=101

return name,roll

Output

 

3. Variable Number of Arguments

In python, it is possible to have variable number of arguments. In that case the parameter name begins with *. Then these variable number of arguments are gathered into a tuple. For example -

Test.py

def student_Info(*args):

print(args)

Output

In above program * accepts the variable number of arguments and inside the function definition, these arguments are printed.

Review Questions

1. Can function return tuples ? If yes give example. AU : Dec.-19, Marks 2

2. Demonstrate with code the various operations that can be performed on tuples. AU : May-19, Marks 16

3. Compare and contrast tuples and lists in Python. AU : Dec.-19, Marks 8

4. What is tuple in Python ? How does it differ from list ? AU : Dec.-19, Marks 8