Creating 2D coordinates map in Python
Solution 1
Using itertools.product()
:
from itertools import product
coordinates = list(product(xrange(width), xrange(height)))
Solution 2
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
Updated on July 09, 2022Comments

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
Solution 1
coordinates = [(x, y) for x in xrange(width) for y in xrange(height)]
Solution 2
coordinates = [] for x in xrange(width): for y in xrange(height): coordinates.append((x, y))
Solution 3
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
itertools
is 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
xrange
in theitertools.product
class would be more memory efficient, like F.J. did. 
senderle almost 12 years@NiklasR, assuming this is Python 2. If it's Python 3,
xrange
no 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
itertools
solution? And you should provide better descriptions for the numbers.