# numpy.c_ = <numpy.lib.index_tricks.CClass object>
#
# Translates slice objects to concatenation along the second axis.
#
#    np.c_  is short-hand for np.r_['-1,2,0', index expression]
#
# which is useful because of its common occurrence. 
#
# In particular, arrays will be stacked along their last axis after 
# being upgraded to at least 2-D with 1’s post-pended to the shape 
# (column vectors made out of 1-D arrays).

import numpy as np

a1 = np.array([1,2,3])
a2 = np.array([4,5,6])

print(a1)
print(a2)

# Make a column array with a1, a2
z = np.c_[ a1, a2 ]
print(z)


# You don't need anything special to row array with a1, a2
z = np.array([a1, a2])
print(z)