Referencing a character's position inside a loop with Python

Question

How can I write a loop in Python that behaves exactly like this JavaScript loop:

for (i = 0; i < cars.length; i++)

That is, I want the variable i to hold the value of the index of the character as I iterate over a string.

Answer 1

This will work for what you would like to do

for i in range(len(cars)):
    print(i)  # 0, 1, 2, 3, 4...

Answer 2

Using the range function combined with len:

for i in range(len(cars)):
      ... cars[i]

Answer 3

Another option is to use enumerate:

for ii, car in enumerate(cars):
    print ii, car

assuming cars is a list like:

cars = ['a', 'b', 'c', 'd']

Then, the output is:

>>> 0 a
>>> 1 b
>>> 2 c
>>> 3 d

Answer 4

Marginally better:

for i in xrange(len(cars)):
    print(i)

xrange is preferable to range in most cases. Best to get in the habit of using xrange.