Iterating over arbitrary dimension of numpy.array

user_79513 0
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Is there function to get an iterator over an arbitrary dimension of a numpy array?

Iterating over the first dimension is easy...

In [63]: c = numpy.arange(24).reshape(2,3,4)

In [64]: for r in c :
   ....:     print r
   ....: 
[[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]]
[[12 13 14 15]
 [16 17 18 19]
 [20 21 22 23]]

But iterating over other dimensions is harder. For example, the last dimension:

In [73]: for r in c.swapaxes(2,0).swapaxes(1,2) :
   ....:     print r
   ....: 
[[ 0  4  8]
 [12 16 20]]
[[ 1  5  9]
 [13 17 21]]
[[ 2  6 10]
 [14 18 22]]
[[ 3  7 11]
 [15 19 23]]

I'm making a generator to do this myself, but I'm surprised there isn't a function named something like numpy.ndarray.iterdim(axis=0) to do this automatically.

numpy python loops
6 Answers

You can use numpy.shape to get dimensions, and then range to iterate over them.

n0, n1, n2 = numpy.shape(c)

for r in range(n0):
    print(c[r,:,:])
user_119034110

The following is exactly what you are looking for:

for x in np.moveaxis(X, axis, 0):
user_93183720
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