How to convert JavaScript `for` loop to Python?

Question

I am new to Python and want convert this small JavaScript code to Python. How can I do that?

for (var y = 0; y < 128; y += 1024) {
 for (var x = 0; x < 64; x += 1024) {
 // skipped
 }
}

I searched a lot in Google, but found nothing.

Answer 1

for loops in Python

It can be easily converted using range() or xrange() function. The xrange() is an iterator version, which means it is more efficient (range() would first create a list you would be iterating through). Its syntax is the following: xrange([start], stop[, step]). See the following:

for y in xrange(0, 128, 1024):
 for x in xrange(0, 64, 1024):
 # here you have x and y

Note

But I hope you have noticed, that due to the fact, that you are incrementing y and x with each respective loop by 1024, you will actually receive something similar to this:

var y = 0;
var x = 0;

or, in Python:

x = 0
y = 0

Anyway, it is just additional note about the code you have given as example.

Answer 2

Your code will only perform one iteration in each loop, so you don't even need a loop:

y = 0
x = 0
# do whatever with x and y here

In general, you can use range([start], stop[, step]) ^[docs] to simulate such a for loop.

For example:

for(var i = 0; i < 10; i += 2)

becomes

for i in range(0, 10, 2)