Numerical Computing with Python

How to do it...

1. Before we get started with the actual flights dataset, let's practice counting streaks of ones with a small sample Series:

>>> s = pd.Series([0, 1, 1, 0, 1, 1, 1, 0])>>> s0    01    12    1
3    0
4    1
5    1
6    1
7    0
dtype: int64

2. Our final representation of the streaks of ones will be a Series of the same length as the original with an independent count beginning from one for each streak. To get started, let's use the cumsum method:

>>> s1 = s.cumsum()>>> s10    0
1    1
2    2
3    2
4    3
5    4
6    5
7    5
dtype: int64

3. We have now accumulated all the ones going down the Series. Let's multiply this Series by the original:

>>> s.mul(s1)0    0
1    1
2    2
3    0
4    3
5    4
6    5
7    0
dtype: int64

4. We have only non-zero values where we originally had ones. This result is ...