Python Tuple

Python Tuple

A tuple is a sequence of immutable objects, therefore tuple cannot be changed. It can be used to collect different types of object.

The objects are enclosed within parenthesis and separated by comma.

Tuple is similar to list. Only the difference is that list is enclosed between square bracket, tuple between parenthesis and List has mutable objects whereas Tuple has immutable objects.

Python Tuple Example

1.   >>> data=(10,20,'ram',56.8)  

2.   >>> data2="a",10,20.9  

3.   >>> data  

4.   (10, 20, 'ram', 56.8)  

5.   >>> data2  

6.   ('a', 10, 20.9)  

7.   >>>  

There can be an empty Tuple also which contains no object. Lets see an example of empty tuple.

Python Empty Tuple Example

1.   tuple1=()  

Python Single Object Tuple Example

For a single valued tuple, there must be a comma at the end of the value.

1.   Tuple1=(10,)  

Python Tuple of Tuples Example

Tuples can also be nested, it means we can pass tuple as an element to create a new tuple. See, the following example in which we have created a tuple that contains tuples an the object.

1.   tupl1='a','mahesh',10.56  

2.       tupl2=tupl1,(10,20,30)  

3.       print tupl1  

4.       print tupl2  

Output:

1.   >>>   

2.   ('a', 'mahesh', 10.56)  

3.   (('a', 'mahesh', 10.56), (10, 20, 30))  

4.   >>>  

Accessing Tuple

Accessing of tuple is prity easy, we can access tuple in the same way as List. See, the following example.

Accessing Tuple Example

1.   data1=(1,2,3,4)  

2.   data2=('x','y','z')  

3.   print data1[0]  

4.   print data1[0:2]  

5.   print data2[-3:-1]  

6.   print data1[0:]  

7.   print data2[:2]  

Output:

1.   >>>   

2.   1  

3.   (1, 2)  

4.   ('x', 'y')  

5.   (1, 2, 3, 4)  

6.   ('x', 'y')  

7.   >>>  

Elements in a Tuple

Data=(1,2,3,4,5,10,19,17)

Data[0]=1=Data[-8] , Data[1]=2=Data[-7] , Data[2]=3=Data[-6] ,   

Data[3]=4=Data[-5] , Data[4]=5=Data[-4] , Data[5]=10=Data[-3],  

Data[6]=19=Data[-2],Data[7]=17=Data[-1]  

Python Tuple Operations

Python allows us to perform various operations on the tuple. Following are the common tuple operations.

Adding Tuples Example

Tuple can be added by using the concatenation operator(+) to join two tuples.

data1=(1,2,3,4)  

data2=('x','y','z')  

data3=data1+data2  

print data1  

print data2  

print data3  

Output:

>>>

(1, 2, 3, 4)

('x', 'y', 'z')

(1, 2, 3, 4, 'x', 'y', 'z')

>>> 

Replicating Tuple Example

Replicating means repeating. It can be performed by using '*' operator by a specific number of time.

tuple1=(10,20,30);  

tuple2=(40,50,60);  

print tuple1*2  

print tuple2*3  

Output:

>>>

(10, 20, 30, 10, 20, 30)

(40, 50, 60, 40, 50, 60, 40, 50, 60)

>>> 

Python Tuple Slicing Example

A subpart of a tuple can be retrieved on the basis of index. This subpart is known as tuple slice.

data1=(1,2,4,5,7)  

print data1[0:2]  

print data1[4]  

print data1[:-1]  

print data1[-5:]  

print data1  

Output:

>>>

(1, 2)

7

(1, 2, 4, 5)

(1, 2, 4, 5, 7)

(1, 2, 4, 5, 7)

>>> 

Python Tuple other Operations

Updating elements in a List

Elements of the Tuple cannot be updated. This is due to the fact that Tuples are immutable. Whereas the Tuple can be used to form a new Tuple.

Example

data=(10,20,30)  

data[0]=100  

print data  

Output:

>>>

Traceback (most recent call last):

       File "C:/Python27/t.py", line 2, in

      data[0]=100

TypeError: 'tuple' object does not support item assignment

>>> 

Creating Tuple from Existing Example

We can create a new tuple by assigning the existing tuple, see the following example.

data1=(10,20,30)  

data2=(40,50,60)  

data3=data1+data2  

print data3  

Output:

>>>

(10, 20, 30, 40, 50, 60)

>>> 

Python Tuple Deleting Example

Deleting individual element from a tuple is not supported. However the whole of the tuple can be deleted using the del statement.

data=(10,20,'rahul',40.6,'z')  

print data  

del data      #will delete the tuple data  

print data  #will show an error since tuple data is already deleted  

Output:

>>>

(10, 20, 'rahul', 40.6, 'z')

Traceback (most recent call last):

      File "C:/Python27/t.py", line 4, in

      print data

NameError: name 'data' is not defined

>>> 

Functions of Tuple

There are following in-built Type Functions

Function	Description
min(tuple)	It returns the minimum value from a tuple.
max(tuple)	It returns the maximum value from the tuple.
len(tuple)	It gives the length of a tuple
cmp(tuple1,tuple2)	It compares the two Tuples.
tuple(sequence)	It converts the sequence into tuple.

Python Tuple min(tuple) Method Example

This method is used to get min value from the sequence of tuple.

data=(10,20,'rahul',40.6,'z')  

print min(data)  

Output:

>>>

10

>>> 

Python Tuple max(tuple) Method Example

This method is used to get max value from the sequence of tuple.

data=(10,20,'rahul',40.6,'z')  

print max(data)  

Output:

>>>

z

>>> 

Python Tuple len(tuple) Method Example

This method is used to get length of the tuple.

data=(10,20,'rahul',40.6,'z')  

print len(data)  

Output:

>>>

5

>>> 

Python Tuple cmp(tuple1,tuple2) Method Example

This method is used to compare tuples.

Explanation:If elements are of the same type, perform the comparison and return the result. If elements are different types, check whether they are numbers.

• If numbers, perform comparison.
• If either element is a number, then the other element is returned.
• Otherwise, types are sorted alphabetically .

If we reached the end of one of the lists, the longer list is "larger." If both list are same it returns 0.

data1=(10,20,'rahul',40.6,'z')  

data2=(20,30,'sachin',50.2)  

print cmp(data1,data2)  

print cmp(data2,data1)  

data3=(20,30,'sachin',50.2)  

print cmp(data2,data3)  

Output:

>>>

-1

1

0

>>> 

5) tuple(sequence):

Eg:

dat=[10,20,30,40]  

data=tuple(dat)  

print data  

Output:

>>>

(10, 20, 30, 40)

>>> 

Why should we use Tuple? (Advantages of Tuple)

1. Processing of Tuples are faster than Lists.
2. It makes the data safe as Tuples are immutable and hence cannot be changed.
3. Tuples are used for String formatting.