Learn how to create, index, slice, reshape, and perform arithmetic operations on arrays using NumPy, the most popular Python library for data science.

the axis along which multiple arrays are concatenated. By default, it is along the first dimension.

/Users/mb312/tmp/ in () ----> 1 np.concatenate((r4, r3), None) ValueError: all the input arrays must have same number of elements The change requiring the same number of elements appears to have been ...