Question

How to get the number of times a number N appears in a nested list with Python

Answer 1

import itertools, collections

nestedlist = [[1, 2, 3], [1, 5], [6, 1, 8, 9, 10], [1, 9, 10, 10], [1]]
N = 1

countN = collections.Counter(itertools.chain(*nestedlist))

print(countN[N])


'''
run:

5

'''

 

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Answer 2

nestedlist = [[1, 2, 3], [1, 5], [6, 1, 8, 9, 10], [1, 9, 10, 10], [1]]
N = 1

countN = sum(x.count(N) for x in nestedlist)

print(countN)


'''
run:

5

'''

 

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