Why enumerate?

This post will discuss the Python enumerate function quickly. Python is known to make code readable and using enumerate will make your code more readable.

Simple loops

Loops let you repeat lines of code, the most common being for loops and while loop. If you have previous experience with for loops, you may be inclined to use an index (i) on the array.

>>> array = ['a','b','c','d','e']
>>> for i in range(len(array)):
...     print(array[i])
... 
a
b
c
d
e
>>> 

If you have been programming during the C++ days, you may even be inclined to do something like this:

>>> i = 0
>>> while i < len(array):
...     print(array[i])
...     i = i + 1

This is overcomplicated. Python is mucher easier

How to use enumerate

This works, but it's not Pythonic. Instead enumerate makes this more readable (It's also easier to code).

The enumerate function takes an iterable (array) and for each element gives the value and index.

>>> array = ['a','b','c','d','e']
>>> for index, item in enumerate(array):
...     print(item)
... 
a
b
c
d
e
>>> 

Much better! You get the index as well as the element, without having to keep track of the index variable.

The enumerate function works on arrays (lists) or other types of sequences like tuples, strings etc.

>>> array = [ 1,3,2,6,3,9,4,12,5,15,6,18,7,21,8 ]
>>> for index, item in enumerate(array):
...     print(item)
... 

So enumerate is a very useful function that makes programming a bit simpler.