Predictive Hacks

Count the Consecutive Events in Python

This short post is about finding an efficient way to count consecutive events. We are going to represent a straightforward practical example:

import pandas as pd
df = pd.DataFrame({'Score':['win', 'loss', 'loss', 'loss', 'win', 'win', 'win', 'win', 'win', 'loss', 'win', 'loss', 'loss']})
df
   Score
0    win
1   loss
2   loss
3   loss
4    win
5    win
6    win
7    win
8    win
9   loss
10   win
11  loss
12  loss

And with the following “hack” we are going to get the column of the “Streak”

df['Streak'] = df['Score'].groupby((df['Score'] != df['Score'].shift()).cumsum()).cumcount() + 1
df
   Score  Streak
0    win       1
1   loss       1
2   loss       2
3   loss       3
4    win       1
5    win       2
6    win       3
7    win       4
8    win       5
9   loss       1
10   win       1
11  loss       1
12  loss       2

Count the Consecutive Events within Group

Let’s say that we have the same example as above, but we want to do the same exercise within group.

df = pd.DataFrame({'Group':['A','A', 'A','A','A','A','B','B','B','B','B','B','B'],
                   'Score':['win', 'loss', 'loss', 'loss', 'win', 'win', 'win', 'win', 'win', 'loss', 'win', 'loss', 'loss']})
df
   Group Score
0      A   win
1      A  loss
2      A  loss
3      A  loss
4      A   win
5      A   win
6      B   win
7      B   win
8      B   win
9      B  loss
10     B   win
11     B  loss
12     B  loss
df['Streak'] = df['Score'].groupby((df['Score'] != df.groupby(['Group'])['Score'].shift()).cumsum()).cumcount() + 1
df
   Group Score  Streak
0      A   win       1
1      A  loss       1
2      A  loss       2
3      A  loss       3
4      A   win       1
5      A   win       2
6      B   win       1
7      B   win       2
8      B   win       3
9      B  loss       1
10     B   win       1
11     B  loss       1
12     B  loss       2

Share This Post

Share on facebook
Share on linkedin
Share on twitter
Share on email

Leave a Comment

Subscribe To Our Newsletter

Get updates and learn from the best

More To Explore

python package
Python

How to Build Python Packages

In this tutorial, we will show you how to build Python Packages. Our goal is to build a Python package