import numpy as np


a = np.array( [ [11,12,13,14,15], [21,22,23,24,25], [31,32,33,34,35] ] )
print(a)

# a particular column is just another 2D rectangular array
# in which each row length is 1.

c = a[:, 1:2]
print( c )

for item in c:
    print( "item", item )

print()


# "Flatten" the column =
# = convert it to array of items not array of arrays,
# it is OK, however the array becomes
# an usual 1D "horizontal" array.

cc = [x[0] for x in c]
for item in cc:
    print( "item", item )


print()
print( c )
print( cc )