Pythonic way to simple array handling

Question

import numpy as np
data = np.array([[2,0,1,2,0],[0,1,2,0,1],[2,0,1,2,2]])

I require the following threes as separate variables

class0 = np.where(data==0)
class1 = np.where(data==1)
class2 = np.where(data==2)

I knew how to write them in three lines as above. However, what is the Pythonic way to do it using the examples below:

classes = ['class0', 'class1', 'class2']
values =[0,1,2]

for x, y in zip(classes, values):
    x = np.where(data == y)
    print x

HERE how can I name the answers resulted by x as class0,class1,class2???

ebarr · Accepted Answer · 2014-03-15 07:51:46Z

1

Dictionary:

classes = ['class0', 'class1', 'class2']
values =[0,1,2]
output = {} #create a dictionary instance

for x, y in zip(classes, values):
    output[x] = np.where(data == y) #use the class name as the dictionary key

answered Mar 15, 2014 at 7:51

ebarr

7,8521 gold badge32 silver badges43 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Gnijuohz · Accepted Answer · 2014-03-15 08:01:10Z

1

Or you can do this if you really want three variables instead of a dictionary:

class0, class1, class2 = [np.where(data == i) for i in range(0, 3)]

This does not fit in the example you gave in the question though.

answered Mar 15, 2014 at 8:01

Gnijuohz

3,3746 gold badges34 silver badges49 bronze badges

Collectives™ on Stack Overflow

Pythonic way to simple array handling

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related