CODEWITHSUNDEEP
pythonpandas
David Berri
David Berri

Reputation: 40

Count of values between other values in a pandas DataFrame

I have a column of a pandas DataFrame that looks like this:

1       False
2       False
3       False
4        True
5        True
6       False
7       False
8       False
9       False
10      False
11      True
12      False

I would like to get the count of False between the True. Something like this:

1      3
2      0
3      5
4      1

This is what I've done:

counts = []
count = 0
for k in df['result'].index:
    if df['result'].loc[k] == False:
        count += 1
    else:
        counts.append(count)
        count = 0

where counts would be the result. Is there a simpler way?

Upvotes: 0

Views: 364

Answers (2)

James
James

Reputation: 36608

You can use the groupby function from the itertools package to group the False and True values together and append the count to a list.

s = pd.Series([False,False,False,True,True,False,False,False,False,False,True,False], 
              index=range(1,13)

from itertools import groupby

out = []
for v,g in groupby(s):
    if not v:  # v is false
        out.append(len(tuple(g)))
    else:      # v is true
        out.extend([0]*(len(tuple(g))-1))


out
[3, 0, 5, 1]

Upvotes: 0

akuiper
akuiper

Reputation: 214927

Group by the cumulative sum of itself and then count the False with sum:

s = pd.Series([False, False, False,  True,  True, False, False, False, False, False,  True, False])

(~s).groupby(s.cumsum()).sum()
#0    3.0
#1    0.0
#2    5.0
#3    1.0
#dtype: float64

Upvotes: 4

Related Questions