Explain what below code does? aa=aa[:22]

Question

Import bumpy as np
aa=no.array([1,2,3,4,5]) # this will generate an array of [1,2,3,4,5]

aa=aa[:22] #???????
aa = np.expand_dims(aa, axis=0)

Answer 1

I don't think 'bumpy' is the right module here, it should be 'numpy'.
According to me, the correct code should be:

import numpy as np
aa=np.array([1,2,3,4,5]) #this will generate as array of [1,2,3,4,5]

aa=aa[:22]
'''
This is pretty meaningless since the array length is 5 which is smaller than 22, so variable 'aa' will remain the same.
It would be more meaningful if 'aa[:2:2]' is used since it will do some manipulation and return alternate elements between indexes 0 and 2.
'''

aa=np.expand_dims(aa,axis=0)
'''
This statement will convert 'aa' form array to matrix i.e., increment in dimension, from 1D(array) to 2D(matrix).
axis=0 is mentioned, therefore the number of columns is increased from 1 to the number of elements in the array, in the case of axis=1, the number of rows will be increased from 1 to the number of elements in the array.
'''

Hope you find this useful.

Answer 2

Thank you Manish. You I had a typo for bumpy it should be numpy