Question

I declared a multidimensional array that can accept different data types using numpy

count_array = numpy.empty((len(list), 2), dtype = numpy.object)

The first array has got strings and the second has got numbers. I want to sort both the columns on the basis of the numbers …

Is there any easier way like sort() method to do this ?

Answer 1

You could argsort the second column, then use so-called “fancy-indexing” on the rows:

import numpy as np
count_array = np.array([('foo',2),('bar',5),('baz',0)], dtype = np.object)
print(count_array)
# [[foo 2]
#  [bar 5]
#  [baz 0]]

idx = np.argsort(count_array[:, 1])
print(idx)
# [2 0 1]

print(count_array[idx])
# [[baz 0]
#  [foo 2]
#  [bar 5]]