I want to declare and populate a 2d array in python as follow:
def randomNo():
rn = randint(0, 4)
return rn
def populateStatus():
status = []
status.append([])
for x in range (0,4):
for y in range (0,4):
status[x].append(randomNo())
But I always get IndexError: list index out of range exception. Any ideas?
You haven't increase the number of rows in status
for every value of x
for x in range(0,4):
status.append([])
for y in range(0,4):
status[x].append(randomNo())
Try this:
def randomNo():
rn = randint(0, 4)
return rn
def populateStatus():
status = {}
for x in range (0,4):
status [x]={}
for y in range (0,4):
status[x][y] = randomNo()
This will give you a 2D dictionary you can access like val=status[0,3]
The only time when you add 'rows' to the status array is before the outer for loop.
So - status[0]
exists but status[1]
does not.
you need to move status.append([])
to be inside the outer for loop and then it will create a new 'row' before you try to populate it.
More "modern python" way of doing things.
[[ randint(0,4) for x in range(0,4)] for y in range(0,4)]
Its simply a pair of nested list comprehensions.
If you're question is about generating an array of random integers , the numpy module can be useful:
import numpy as np
np.random.randint(0,4, size=(4,4))
This yields directly
array([[3, 0, 1, 1],
[0, 1, 1, 2],
[2, 0, 3, 2],
[0, 1, 2, 2]])
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