Part7-Tuple.md

Tuples in Python

What is tuple?

A tuple is a collection of objects or sequences just like lists.Tuples are used to store multiple items in a single variable. The differences between tuples and lists are lists are mutable, whereas tuples are immutable it means cannot be changed. Unlike lists and tuples use parentheses, whereas lists use square brackets.You can access tuple items by referring to the index number, inside square brackets and index number starts from 0.

Syntax

Example1

tuple1 = ()  #Empty Tuple
print("Output:\n")
print("tuple1 is empty:",tuple1)

Output:

tuple1 is empty: ()

Example2

tuple2 = ("apple", "banana", "cherry")     #Tuple Items
print("Output:\n ")
print(tuple2)

Output:
 
('apple', 'banana', 'cherry')

Tuple Advantages over List

1. Program execution is faster when manipulating a tuple than it is for the equivalent list.
2. Sometimes you don’t want data to be modified. If the values in the collection are meant to remain constant for the life of the program, using a tuple instead of a list guards against accidental modification.
3. There is another Python data type that you will encounter shortly called a dictionary, which requires as one of its components a value that is of an immutable type. A tuple can be used for this purpose, whereas a list can’t be.

How to Access Tuple Items

• Print the second item in the tuple

tuple2 = ("apple", "banana", "cherry")      #Accessing tuple items
print("Output:\n ")
print(tuple2[1])

Output:
 
banana

Negative Indexing

• Print the last item of the tuple

tuple2 = ("apple", "banana", "cherry")  #Accessing last item
print("Output:\n ")
print(tuple2[-1])

Output:
 
cherry

Range of Indexes / Slicing

• You can specify a range of indexes by specifying where to start and where to end the range.

• When specifying a range, the return value will be a new tuple with the specified items.

Example

• Return the third, fourth, and fifth item

tuple2 = ("apple", "banana", "cherry", "orange", "kiwi", "melon", "mango")   #slicing
print("Output:\n ")
print(tuple2[2:5])

Output:
 
('cherry', 'orange', 'kiwi')

Change Tuple Values

Once a tuple is created, you cannot change its values. Tuples are unchangeable, or immutable. But there is a workaround. You can convert the tuple into a list, change the list, and convert the list back into a tuple.

Convert the tuple into a list to be able to change it

For Example

x = ("apple", "banana", "cherry")  
y = list(x)                                  #Changing tuple to list
y[1] = "kiwi"                                #Adding item in list
x = tuple(y) 
print("Output:\n ")

print(x)

Output:
 
('apple', 'kiwi', 'cherry')

Remove Items

• Note: You cannot remove items in a tuple.

Tuples are unchangeable, so you cannot remove items from it, but you can use the same workaround as we used for changing and adding tuple items.

Example

tuple2 = ("apple", "banana", "cherry")
y = list(tuple2)
y.remove("apple")                     #Removing the item 'apple'
tuple2 = tuple(y)
print("Output:\n ")                   #After Removal
print(tuple2)

Output:
 
('banana', 'cherry')

Loop Through a Tuple

You can loop through the tuple items by using a for loop.

Iterate through the items and print the values

Example

tuple2 = ("apple", "banana", "cherry")
print("Output:\n") 
for x in tuple2: 
  print(x)

Output:

apple
banana
cherry

Basic Operations of Tuple

Python Expression	Result	Operation
(1,2,3)+(8,9,9)	(1,2,3,8,9,9)	Concatination
len((4,5,6))	3	Length
7 in (1,4,7)	True	Membership
for n in (1,3,5):print (n)	1 3 5	Iteration

Built-in Function of Tuple

Function	Description
cmp(tuple1,tuple2)	It compares two tuples and returns true if tuple1 is greater than tuple2 otherwise false.
len(tuple)	It calculates the length of the tuple.
max(tuple)	It returns the maximum element of the tuple.
min(tuple)	It returns the minimum element of the tuple.
tuple(seq)	It converts the specified sequence to the tuple.