Python Setting Values Given Two Column

I have 2 time series data frames. Both contain values [0,1] only. The first one is called init_signal and the second is called end_signal. The idea is to create a new dataframe when init_signal has a 1, it will find the NEXT 1 in end_signal.

Example below merges both the init_signal and end_signal as one dataframe. the first column is init_signal and the second column is end_signal.

For example:

2016-06-13  1  0
2016-06-14  0  0
2016-06-15  0  1
2016-06-16  0  0

Will become:

2016-06-13  1  
2016-06-14  1  
2016-06-15  1  
2016-06-16  0  

For example 2:

2016-06-13  1  1
2016-06-14  0  0
2016-06-15  0  1
2016-06-16  0  0

Will become:

2016-06-13  1  
2016-06-14  1  
2016-06-15  1  
2016-06-16  0  

In the 2nd example, if there is also a 1 in the same row as the init_signal, it will be ignored.

I've been using a complex loop. Is there a non-looping way?

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