Accessing the index in 'for' loops?

python loops list
Joan Venge picture Joan Venge · Feb 6, 2009 · Viewed 2.3M times · Source

How do I access the index in a for loop like the following?

ints = [8, 23, 45, 12, 78]
for i in ints:
    print('item #{} = {}'.format(???, i))

I want to get this output:

item #1 = 8
item #2 = 23
item #3 = 45
item #4 = 12
item #5 = 78

When I loop through it using a for loop, how do I access the loop index, from 1 to 5 in this case?

Answer

Mike Hordecki picture Mike Hordecki · Feb 6, 2009

Using an additional state variable, such as an index variable (which you would normally use in languages such as C or PHP), is considered non-pythonic.

The better option is to use the built-in function enumerate(), available in both Python 2 and 3:

for idx, val in enumerate(ints):
    print(idx, val)

Check out PEP 279 for more.

Related questions

Python - TypeError: 'int' object is not iterable

Here's my code: import math print "Hey, lets solve Task 4 :)" number1 = input ("How many digits do you want to look at? ") number2 = input ("What would you like the digits to add up to? ") if number1 == 1: cow = range(0,10) elif number1 == 2: cow = …

Read More
How do I loop through a list by twos?

I want to loop through a Python list and process 2 list items at a time. Something like this in another language: for(int i = 0; i < list.length(); i+=2) { // do something with list[i] and list[i + 1] } What's the best …

Read More
Creating a list of objects in Python

I'm trying to create a Python script that opens several databases and compares their contents. In the process of creating that script, I've run into a problem in creating a list whose contents are objects that I've created. I've simplified …

Read More