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
>>> data=(10,20,'ram',56.8) 
>>> data2="a",10,20.9 
>>> data 
(10, 20, 'ram', 56.8) 
>>> data2 
('a', 10, 20.9) 
>>> 

NOTE: If Parenthesis is not given with a sequence, it is by default treated as Tuple.
There can be an empty Tuple also which contains no object. Lets see an example of empty tuple.

Python Empty Tuple Example
tuple1=() 

Python Single Object Tuple Example
For a single valued tuple, there must be a comma at the end of the value.
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.

tupl1='a','mahesh',10.56 
    tupl2=tupl1,(10,20,30) 
    print tupl1 
    print tupl2 

Output:
>>>  
('a', 'mahesh', 10.56) 
(('a', 'mahesh', 10.56), (10, 20, 30)) 
>>> 

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
data1=(1,2,3,4) 
data2=('x','y','z') 
print data1[0] 
print data1[0:2] 
print data2[-3:-1] 
print data1[0:] 
print data2[:2] 

Output:
>>>  
1 
(1, 2) 
('x', 'y') 
(1, 2, 3, 4) 
('x', 'y') 
>>> 

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')
>>>

Note: The new sequence formed is a new Tuple.

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)
>>>

Note: If the index provided in the Tuple slice is outside the list, then it raises an IndexError exception.

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 wee use Tuple? (Advantages of Tuple)

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