CODEWITHSUNDEEP
pythonpython-itertoolscartesian-product
Harshad Surdi
Harshad Surdi

Reputation: 23

Why does a cartesian product yield "TypeError: iteration over a 0-d array"?

I am trying to make a cartesian product from a list of arrays but it keeps giving me a TypeError: iteration over a 0-d array

I have a list which looks like:

print(a)
>>>[array([1., 2.]), array([3., 4.]), array(1400.)]

Now, when I try to do:

b=list(itertools.product(*a))
>>>TypeError: iteration over a 0-d array

What am I missing?

Upvotes: 2

Views: 176

Answers (1)

Sheldore
Sheldore

Reputation: 39052

As explained by @user2357112 in the comments, you currently have the last element as a 0 dimensional array. If you check the length of it, you will get TypeError: len() of unsized object. To get your solution working, you need to enclose the element in the last array using [] to be able to use the product 

import itertools

a = [np.array([1., 2.]), np.array([3., 4.]), np.array([1400.])]

b = list(itertools.product(*a))

#[(1.0, 3.0, 1400.0),
# (1.0, 4.0, 1400.0),
# (2.0, 3.0, 1400.0),
# (2.0, 4.0, 1400.0)]

Edit answering second question on request:

import itertools

dict1 = {'wdth_i': ['1', '2'], 'wdth_p': ['3', '4'], 'mu': '1400'}

a = [] 
for i in dict1.values():
    if isinstance(i, list):
        a.append(i)  
    else:
        a.append([i])

f = list(itertools.product(*a))
# [('1', '3', '1400'),
#  ('1', '4', '1400'),
#  ('2', '3', '1400'),
#  ('2', '4', '1400')]

Upvotes: 2

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