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Today we are going to understand one of Python's most important collection data types, tuple. A tuple is an ordered sequence of items. The items of a tuple are arranged in the order in which they are declared in a tuple, where the first item is stored at the index zero, the second item at the index one and so on.

• Important properties of tuple



• A tuple is immutable i.e. existing items cannot be modified and we cannot insert new items to it.
• We can store duplicate values in a tuple.
• Each item in a tuple is accessible through its index.







• How to create a tuple in Python?


In order to create a tuple with items, we must declare its items within a pair of parentheses ( ), where each item is separated by a comma(,) operator. Let us show you a simple example of how to create a tuple with items.



#Python - Creating a tuple with items


customer =('Edward', 27, 178.5, 'M')
print(customer)




Output




('Edward', 27, 178.5, 'M')


In the example above, we have created a tuple named customer, containing 4 items which are separated by the comma(,) operator and all items are enclosed within a pair of parenthesis ( ). The items of tuple are displayed in the order in which they were declared within a tuple.






• Extracting each item of a tuple


Items of a tuple are stored by using the zero-based indexing i.e. the first item of a tuple is stored at the index zero , second element at the index one and so on.



#Python - Extracting each time of a tuple using its index.


misc =(2 ,-19, 17.5, 'have a good day!')
print(misc)
print(misc[0])
print(misc[1])
print(misc[2])
print(misc[3])




Output




(2, -19, 17.5, 'have a good day!')
2
-19
17.5
have a good day!


In the example above, we have created a tuple named misc, which contains 4 items separated by a comma , and are enclosed within a pair of parenthesis ( ).
Next, we have accessed each item of a tuple by accessing its index position:
• The first tuple element 2 is accessed using its index position 0
• The second tuple element -19 is accessed using its index position 1
• The third tuple element 17.5 is accessed using its index position 2
• The fourth tuple element have a good day is accessed using its index position 3





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• Iterating over items in a tuple using for loop


Using the in membership operator with for loop, allows us to iterate over items within a tuple. Let us see how we do this.



#Python - Iterating over items in a tuple using for loop

# Creating a tuple
misc =(2 ,-19, 17.5, 'have a good day!')

# Using for loop to iterate over items in a tuple
for val in misc:
        print(val)




Output




2
-19
17.5
have a good day!








• A tuple is immutable


Once we have declared a tuple with its items, it is immutable i.e. its existing items cannot be modified and we cannot insert or append new items to it. Let us prove this by an example.



#Python - Tuple once declared in immutable


misc2 =(2 ,-19, 17.5, 'have a good day!')

#Trying to insert a new item at index 1 in a tuple - Invalid!
misc2[1]= 5




Output




Traceback (most recent call last):
  File "D:/Python Programs/tuple3.py", line 6, in <module>
    misc2[1]= 5
TypeError: 'tuple' object does not support item assignment


In the example above, we have first created a tuple named misc2 with 4 items and next we have tried to insert a new item at its index 1, which has raised a compile error. The error says that a tuple does not support individual item assignment by using its index position, which also says that we can only create a tuple with its elements, while declaring it.






• Methods of tuple


Now let us discuss two important methods of tuple collection data type - index() and count().



Methods	Description
index()	To find the index of an item in a tuple.
count()	To find the number of times an item exists in a tuple.








• To find the index of an item in a tuple - index() method


We can use the index() method of the tuple data type, to find the first index of an item within a tuple. This method takes an item(whose index is to be searched) as an argument and returns its first index(if found) or else, it reports a ValueError, if the searched item is not found in a tuple.



#Python - Using the index() method  of tuple data type


misc =(2 ,-19, 17.5, 'have a good day!', 17.5)
print('First index of item 17.5 : ', misc.index(17.5)))




Output




First index of item 17.5 : 2


The above program finds the first index of item 17.5, which exists twice within the searched tuple but the method index() returns only the first index of the searched item.






• To find the number of times an item exists in a tuple - count() method


We can store duplicate items in a tuple and this raises a question - if we can find the number of times a specific item exists in a tuple? The answer is, yes!

The tuple data type gives us another important method count, using which we can find the total number of times an item exists in a tuple. This method takes the value of an item(to be searched) as its argument and returns the total number of times it is contained in a tuple.



#Python - Using the count() method with a tuple


misc =(5 , 'have a good day!', 5)
print('Total number of times item 5 is contained in a tuple : ', misc.count(5))




Output




Total number of times item 5 is contained in a tuple : 2








• To find the total number of items in a tuple


We can use the len() function to find the total number of items in a tuple. This function takes a tuple as an argument and returns the total number of items it contains.



#Python - Using len() function with a tuple


misc =(2 ,-19, 17.5, 'have a good day!')
print('Total number of elements in tuple : ', len(misc))




Output




Total number of elements in tuple : 4








• Concatenating tuples using the arithmetic + operator

We could even create a new tuple by concatenating different tuples by using the arithmetic + operator. The arithmetic + operator is overloaded to add integers, floating values, concatenate string values and concatenate tuples.

#Python - Concatenating tuples using the arithmetic + operator


#First tuple
tup1 =('A', -20)

#Second tuple
tup2 =('have a good day', 2019)

#Printing tuples
print('Tuple1 : ', tup1)
print('Tuple2 : ', tup2)

#Creating a new tuple by concatenating existing tuples
tup3 = tup1 + tup2

#Printing new tuple
print('Tuple3 : ',tup3)

Output

Tuple1 :  ('A', -20)
Tuple2 :  ('have a good day', 2019)
Tuple3 :  ('A', -20, 'have a good day', 2019)

In the program just above, we have created two tuples and have then created a third one by concatenating the first two tuples by using the arithmetic + operator.

Some important built-in functions to work with tuple

Functions	Description
max()	Returns the maximum value in a tuple.
min()	Returns the minimum value in a tuple.
len()	Returs the total length of a tuple.
sum()	Returns sum of all elements in a tuple.
sorted()	Returns a sorted copy of a tuple.
any()	Returns true if any element in a tuple is true, else false.
all()	Returns true if all elements in a tuple are true, else false.

#Python - Functions working with tuples 


#First tuple
tup1 =(19, -20, 209, 799.99, -15.4)

#Second tuple
tup2 =(1, True, False, 0) # 1 is boolean true, 0  for boolean false
                          # True(with capital T) is boolean true, False(with capital F) is boolean false

#Printing tuples
print('Tuple1 : ', tup1)
print('Tuple2 : ', tup2)



#Using max() function with a tuple.
print('Maximum value in Tuple1 : ', max(tup1))


#Using min() function with a tuple.
print('Minimum value in Tuple1 : ', min(tup1))


#Using sum() function with a tuple.
print('Sum of values in Tuple1 : ', sum(tup1))


#Using sorted() function with a tuple.
print('Sorted copy of Tuple1 : ', sorted(tup1))


#Using all() function with a tuple.
print('all() boolean true values in Tuple2 : ', all(tup2))


#Using any() function with a tuple.
print('any boolean true value in Tuple2 : ', any(tup2))

Output

Tuple1 :  (19, -20, 209, 799.99, -15.4)
Tuple2 :  (1, True, False, 0)
Maximum value in Tuple1 :  799.99
Minimum value in Tuple1 :  -20
Sum of values in Tuple1 :  992.59
Sorted copy of Tuple1 :  [-20, -15.4, 19, 209, 799.99]
all() boolean true values in Tuple2 :  False
any boolean true value in Tuple2 :  True

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