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Count items in a nested list

The following Python code should make it clear what I would like to execute.

# Say I have the following list and I want to keep count of 1 while going through each nested list L = [[1,1,0,0,0,1],[1,1,0,0,0,0],[0,0,0,0,0,1],[1,1,1,1,1,1]] # So I'd like to get a list containing [3, 5, 6, 12] # I tried to find a compact way of doing this by mapping this list into a another list like such T = [L[:i].count(1) for i in range(len(L))] # >>> [0, 0, 0, 0] # But this doesn't work so how to count occurances for nested lists? # Is there a compact way of doing this (maybe with Lambda functions)? # I'd like to avoid using a function like: def Nested_Count(): Result = [] count = 0 for i in L: count += i.count(1) Result.append(count) return Result # >>> [3, 5, 6, 12]

Please let me know if this is possible or not in order to have a more compact code for this.

Thanks!

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2 answers
 [sum([x.count(1) for x in L[:i]]) for i in range(1, len(L) + 1)]

should do what you want.

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Use sum and list comprehension.

 L = [[1,1,0,0,0,1],[1,1,0,0,0,0],[0,0,0,0,0,1],[1,1,1,1,1,1]] L2 = [sum(x) for x in L] T = [sum(L2[:x+1]) for x in xrange(len(L2))]
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Source: https://habr.com/ru/post/1501111/

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