Creating 2D coordinates map in Python
from itertools import product coordinates = list(product(xrange(width), xrange(height)))
The first solution is elegant, but you could also use a generator expression instead of a list comprehension:
((x, y) for x in range(width) for y in range(height))
This might be more efficient, depending on what you're doing with the data, because it generates the values on the fly and doesn't store them anywhere.
This also produces a generator; in either case, you have to use
list to convert the data to a list.
>>> list(itertools.product(range(5), range(5))) [(0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (1, 0), (1, 1), (1, 2), (1, 3), (1, 4), (2, 0), (2, 1), (2, 2), (2, 3), (2, 4), (3, 0), (3, 1), (3, 2), (3, 3), (3, 4), (4, 0), (4, 1), (4, 2), (4, 3), (4, 4)]
Note that if you're using Python 2, you should probably use
xrange, but in Python 3,
range is fine.
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aemdy over 1 year
I'm not looking for solution, I'm looking for a better solution or just a different way to do this by using some other kind of list comprehension or something else.
I need to generate a list of tuples of 2 integers to get map coordinates like [(1, 1), (1, 2), ..., (x, y)]
So I have the following:
width, height = 10, 5
coordinates = [(x, y) for x in xrange(width) for y in xrange(height)]
coordinates =  for x in xrange(width): for y in xrange(height): coordinates.append((x, y))
coordinates =  x, y = 0, 0 while x < width: while y < height: coordinates.append((x, y)) y += 1 x += 1
Are there any other solutions? I like the 1st one most.
hochl almost 12 yearsI'm fairly sure solution 1 is the best you can come up with.
cheeken almost 12 years
itertoolsis a computational saviour.
asthasr almost 12 years+1. I would put it in a function, so that you can just pass in width and height and get the list back.
Niklas R almost 12 yearsUsing
itertools.productclass would be more memory efficient, like F.J. did.
senderle almost 12 years@NiklasR, assuming this is Python 2. If it's Python 3,
xrangeno longer exists. Adding a note though.
aemdy almost 12 yearsWell, I've just done some testing and got the following: creating a generator by list comprehension without  is the fastest way, but if we are looping through the data afterwards then your method is much faster. Thanks!:)
LWZ over 10 yearsI assume the first implementation is F.J.'s
itertoolssolution? And you should provide better descriptions for the numbers.