np.where return error: ValueError: operands could not be broadcast together with shapes (9,) (0,) (0,)

Joson Hui 0
Viewed 29

I am new to learning numpy. I write the statement as follows to count the number of Buy and Sell, but doesnt work.

count = np.where(((df.Buy == 1) & (df.Sell== 0)),  count + 1, count)

and return error message:

ValueError: operands could not be broadcast together with shapes (9,) (0,) (0,)

Any suggestion. Thanks

pandas numpy python
2 Answers

It looks like you're attempting to count how many times Buy == 1 and Sell == 0 at the same time. One way to do this is:

count = ((df.Buy == 1) & (df.Sell== 0)).sum()
Robert Robison0

Or you can use this as well:

count = df.query('(Buy == 1) and (Sell == 0)').shape[0]
userl4d810
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