CODEWITHSUNDEEP
python-3.xdataframe
PretendNotToSuck
PretendNotToSuck

Reputation: 404

Python: How do I count each number of False occurences between Trues?

This is a column in my dataframe df:

Price  Peak
10     False
15     True
12     False
13     False
12     False
11     False
18     True
13     False
12     False
20     True

I want to count the waiting times between Trues. Desired output in this example would be:

[1, 4, 2]

How would I achieve this most efficiently? Thanks!

Upvotes: 0

Views: 42

Answers (3)

Simonwii
Simonwii

Reputation: 32

This should do it /sw

peak = [False,True,False,False,False,False,True,False,False,True]
out_list = []
iCounter = 0
for _i in range(len(peak)):
    if peak[_i] == True:
        out_list.append(iCounter)
        iCounter = 0
    else:
        iCounter += 1
print(out_list)

Upvotes: 1

shx2
shx2

Reputation: 64328

You can use itertools.groupby().

[
    len(list(b_iter))
    for b, b_iter in itertools.groupby(a)
    if not b
]

Where len(list(b_iter)) is just one way to get the length of an iterator. There are others, e.g. sum(1 for x in b_iter)

Upvotes: 1

Karan Shishoo
Karan Shishoo

Reputation: 2802

You could probably get the output by using something similar to -

count = 0
output = []
For x in df.peak:
    if x:
        output.append(count)
        count = 0
    else:
        count +=1

Basically you iterate over the column and use a counter to keep track of values. at the end of it all, output will be the array that your are looking for

Upvotes: 1

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