Count sequential number of occurrence of items in list

1

Hi there, I’m trying to run a counting operation on a true/false boolean list. Within a list of values, I want to count any continuous sequential occurrences of “false” BEFORE the 1st true, then also count any continuous sequential occurrences of “false” AFTER the last true. Is there a data structure that will do this? I tried starting with getting the index of the occurrences but I got stuck because it only lists the index of the first occurrence. So in this example I would get (1,0),(1,1),(1,1)… and so on

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for something like this:

false
false
true
false
true
false
false

I should get: (2,2)

Thanks!

2

Answered my own question! Used the List.FirstIndexOf to get number BEFORE and then reversed the list to the get number AFTER!

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Hope this helps others who are having the same issue!

Thanks

3

@dgudgenov Or you can do something like this:

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from itertools import groupby
OUT = []
for i in IN[0]:
	gc,keys,temp = [],[],[]
	for k,g in groupby(i):
		keys.append(k)
		if k is not True:
			gc.append(len(list(g)))
			
	if len(gc) == 1:
		if keys[0] == True:
			temp.append([0,gc[0]])
		else:
			temp.append([gc[0],0])
	elif len(gc) > 1:
		if keys[-1] == True:
			temp.append([gc[0],0])
		else:
			temp.append(gc[::len(gc)-1])
	else:
		temp.append(gc)
	
	OUT.append(*temp)