How to number and output objects using Python enumerate()

Python enumerate() is used to output an input as an enu­mer­a­tion object. You can use the in­te­grat­ed function to number strings and lists, among other things.

What is Python enumerate()?

The Python function enumerate() is used to turn an input into an enu­mer­a­tion. The objects, which can also be strings or Python tuples, for example, are each assigned a counter. The enu­mer­a­tion is con­sec­u­tive and starts at “0” by default. The function is included in the pro­gram­ming language by default.

What is the syntax and parameter of Python enumerate()?

The syntax of Python enumerate() looks like this:

enumerate(iterable, start)

It has two pa­ra­me­ters:

• iterable: “iterable” is an object or a sequence that can be executed in a loop. This parameter is placed in front of the enu­mer­a­tion later on. It is mandatory.
• start: This is an optional parameter. You can use it to determine from which numerical value the numbering should start. Its default value is “0”.

Example of an enu­mer­a­tion with enumerate()

To il­lus­trate how this works, let’s choose a simple example with four different colors. We number these using Python enumerate(). The cor­re­spond­ing code looks like this:

colors = ['Blue', 'Red', 'Yellow', 'Orange']
sequence = enumerate(colors)
print(list(sequence))

This is how we get this output:

[(0, 'Blue'), (1, 'Red'), (2, 'Yellow'), (3, 'Orange')]

Python enumerate() with a start index

As we have not specified a start index, the enu­mer­a­tion starts at “0”. To change this, we add the parameter “start” with the value “1” to Python enumerate(). To do this, we slightly change the code from above:

colors = ['Blue', 'Red', 'Yellow', 'Orange']
sequence = enumerate(colors, 1)
print(list(sequence))

This makes the output look a little nicer:

[(1, 'Blue'), (2, 'Red'), (3, 'Yellow'), (4, 'Orange')]

However, you can adjust the start index as you wish so that the enu­mer­a­tion can also begin with any other value.

Enumerate() function with a for loop

In com­bi­na­tion with a for loop, we can combine the use of Python enumerate() with and without start index. For the first loop, we don’t need the “start” parameter. The count therefore starts at “0”. For the second loop, we include the parameter with the starting point “5”. Therefore, this count starts from here. With the "\n" label, we instruct the system to create a new line each time so that it is a little clearer. This is the code for this com­bi­na­tion:

colors = ['Blue', 'Red', 'Yellow', 'Orange']
for sequence in enumerate(colors):
    print(sequence)
    print("\n")
print("It continues from 5")        
for sequence in enumerate(colors, 5):
    print(sequence)
    print("\n")

Our output now looks like this:

(0, 'Blue')
(1, 'Red')
(2, 'Yellow')
(3, 'Orange')
It continues from 5
(5, 'Blue')
(6, 'Red')
(7, 'Yellow')
(8, 'Orange')

How to enumerate strings with Python enumerate()

As the name suggests, Python enumerate() is also the right choice if you want to enumerate a string. This breaks down the string into its in­di­vid­ual parts and numbers them. This is what the code looks like:

string = "example"
for x in enumerate(string, 1):
    print(x)

This is the right output:

(1, 'e')
(2, 'x')
(3, 'a')
(4, 'm')
(5, 'p')
(6, 'l')
(7, 'e')