Enumerate In Python: Iterables, Iterators, and the Eumerate Function

In Python, when we loop over a list or array, we generally use the for loop iterator and iterate over the list's elements one by one. But many times, we come across scenarios where we want the list elements and their index values. In that case, we can either use the range function with list length or Python's inbuilt enumerate function. In this article, we will discuss enumerate in Python and how to use it.

Enumerate() in Python

enumerate(iterable, start)

• The iterable could be a list, string, tuple, dictionary, or set.
• The start parameter is optional, and it represents the counter number. By default, its value is 0.

The enumerate function returns a enumerate iterable object.

Code Example

>>> fruits = ['apple', 'orange', 'grapes', 'banana']
>>> enumerate(fruits)
<enumerate object at 0x0000020C8E809AC0>

fruits = ['apple', 'orange', 'grapes', 'banana']

for index, value in enumerate(fruits):
    print(index, value)

0 apple
1 orange
2 grapes
3 banana

Code Example

fruits = ['apple', 'orange', 'grapes', 'banana']

#start the counter value from 1
for index, value in enumerate(fruits, start=1):
    print(index, value)

Output

1 apple
2 orange
3 grapes
4 banana

Enumerate Object

The enumerate object returned by the enumerate function includes the iterable object in the following order:

(0, element1), (1, element2), (2, element3), (3, element4)...

As the enumerate object is iterable, we can use the for loop to access all the elements of the object. We can also use type conversion and convert the enumerate object into a Python list using the list() function. With that, we can easily check how the enumerate object saves elements.

Code Example

fruits = ['apple', 'orange', 'grapes', 'banana']
enum_obj = enumerate(fruits)

#convert enumerate object to a list
my_bucket = list(enum_obj)

print(my_bucket)

Output

[(0, 'apple'), (1, 'orange'), (2, 'grapes'), (3, 'banana')]

Enumerate List

Python list is also an iterable object, and it can be enumerated using the Python enumerate function. When we enumerate a list using the enumerate function, we get an enumerated iterable object, which is a collection of index and element values tuples.

Code Example

fruits = ['apple', 'orange', 'grapes', 'banana']

for index, element in enumerate(fruits):
    print("Index:",index, "Element:", element )

Output

Index: 0 Element: apple
Index: 1 Element: orange
Index: 2 Element: grapes
Index: 3 Element: banana

Enumerate Tuple

A tuple is an immutable data container that stores elements in sequential order. Similar to the Python list, we can enumerate Python tuple elements with their corresponding index values.

Code Example

#tuple
fruits = ('apple', 'orange', 'grapes', 'banana')

for index, element in enumerate(fruits):
    print("Index:",index, "Element:", element )

Output

Index: 0 Element: apple
Index: 1 Element: orange
Index: 2 Element: grapes
Index: 3 Element: banana

Enumerate String

A string is a collection of characters, and it also stores all its characters in sequential order. The string is also an iterable object and can be enumerated using the Python enumerate function.

Code Example

#given string
string = "Hello World!"

for index,character in enumerate(string):
    print("Index:",index, "Character:", character )

Output

Index: 0 Character: H
Index: 1 Character: e
Index: 2 Character: l
Index: 3 Character: l
Index: 4 Character: o
Index: 5 Character: 
Index: 6 Character: W
Index: 7 Character: o
Index: 8 Character: r
Index: 9 Character: l
Index: 10 Character: d
Index: 11 Character: !

Enumerate Python Dictionary

When we perform the enumerate() function on a dictionary object , the function enumerates the dictionary keys and not the values.

Code Example

#given dictionary
my_dict={"key1":"value1", "key2": "value2", "key3":"value3"}

for index,key in enumerate(my_dict):
    print("Index:",index, "Key:", key )

Output

Index: 0 Key: key1
Index: 1 Key: key2
Index: 2 Key: key3

To enumerate dictionary values, we can use the dictionary values() function.

Code Example

#given dictionary
my_dict={"key1":"value1", "key2": "value2", "key3":"value3"}

for index,value in enumerate(my_dict.values()):
    print("Index:",index, "Value:", value )

Output

Index: 0 Value: value1
Index: 1 Value: value2
Index: 2 Value: value3

Enumerate Set

A Python set is a collection of unique elements, and it neither stores its elements in sequential order, nor it gives index values to its elements. Like tuple and list, Python sets are also iterable objects, and we can enumerate them using the enumerate function.

Code Example

#given set
fruits = {'apple', 'orange', 'grapes', 'banana'}

for counter, element in enumerate(fruits):
    print("Counter:",counter, "Element:", element )

Output

Counter: 0 Element: grapes
Counter: 1 Element: banana
Counter: 2 Element: orange
Counter: 3 Element: apple

Conclusion

With this, let's conclude our article on the Python enumerate function. The enumerate function comes very handily when we want to grab the index number and element of a list or tuple at the same time inside a for loop. The enumerate function just assigns a counter integer number to the iterable object elements and returns an enumerate object.

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