in python TypeError: unhashable type: 'numpy.ndarray'

Question

I tried to find recall but type error occur

import pandas as pd
y_test = {'o1':  [0,1,0,1],'o2': [1,1,0,1],'o3':[0,0,1,1]}
y_test = pd.DataFrame (y_test)
y_pred = {'o1':  [1,1,0,1],'o2': [1,0,0,1],'o3':[1,0,1,1]}
y_pred = pd.DataFrame (y_pred)
y_pred = y_pred.to_numpy()


def precision(y_test, y_pred):
    i = set(y_test).intersection(y_pred)
    len1 = len(y_pred)
    if len1 == 0:
        return 0
    else:
        return len(i) / len1

print("recall of Binary Relevance Classifier: " + str(precision(y_test, y_pred)))

This code shown an error: actually i try to find recall for multi label classification error details iven below

TypeError                                 Traceback (most recent call last)
<ipython-input-41-8f3ca706a8e6> in <module>
16         return len(i) / len1
17 
---> 18 print("recall of Binary Relevance Classifier: " + str(precision(y_test, y_pred)))
<ipython-input-41-8f3ca706a8e6> in precision(y_test, y_pred)
 9 
10 def precision(y_test, y_pred):
---> 11     i = set(y_test).intersection(y_pred)
 12     len1 = len(y_pred)
 13     if len1 == 0:

TypeError: unhashable type: 'numpy.ndarray'

Please add the full error traceback to your question.

Klaus D.
– Klaus D.

2020-08-19 12:47:46 +00:00
Commented Aug 19, 2020 at 12:47 — Klaus D.
– Klaus D., Commented Aug 19, 2020 at 12:47

rajah9 · Accepted Answer · 2020-08-19 13:18:19Z

6

Your numpy array y_test cannot be converted to a set (on line 11), because the array is 2 dimensional.

For an iterable to be converted to a set, the items need to all be hashable. For a 1-d numpy array that's fine, because numbers are hashable:

>>> array_1d = np.array([1, 2, 3])
>>> array_1d
array([1, 2, 3])
>>> set(array_1d)
{1, 2, 3}

But for a 2-d array, you'll get this error because the nested arrays are not themselves hashable:

>>> array_2d = np.array([[1,2,3], [1,2,3], [1,2,3]])
>>> array_2d
array([[1, 2, 3],
       [1, 2, 3],
       [1, 2, 3]])
>>> set(array_2d)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unhashable type: 'numpy.ndarray'

edited Aug 19, 2020 at 13:18

rajah9

12.5k5 gold badges49 silver badges59 bronze badges

answered Aug 19, 2020 at 13:14

Carolyn Conway

1,5461 gold badge17 silver badges21 bronze badges

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

Collectives™ on Stack Overflow

in python TypeError: unhashable type: 'numpy.ndarray'

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related