Str.__contains__() method in conjunction with pd.where() not giving expected results

AI & Machine learning
1

Course Name: EPAT, Section No: 4, Unit No: 2, Unit type: Video



Hi,

I want to filter futures positions in the file <netpositions.csv> such that all rows containing non futures positions get deleted. eg  rows containing :-



        ADANIENT

        AXISBANK-OS-29JUL21-780.00-CE etc.



get deleted but rows such as :-



    ABFRL-FS-29JUL21  (containing '-FS-')



are retained.



I am using the following code



sl_batch_file = net_positions.where(

    

    (net_positions['netTrdQtyLot'] != 0) & (str.contains(str(net_positions['instrumentName']),'-FS-') == True)

    

)



sl_batch_file.dropna(subset = ['netTrdQtyLot']).T      



This code correctly deletes Spot scrips like ADANIENT but does not delete rows containing options contracts like AXISBANK-OS-29JUL21-780.00-CE.



What is happening here? and How can I make it work correctly?



Files are available in the link:

https://drive.google.com/drive/folders/1xhlyK0ixou1HfjBrcvQRgVkXy6_p9Tt8?usp=sharing

2

Hi Anurag.



Try this out!



net_positions = pd.read_csv('netpositions.csv')

net_positions = net_positions[~net_positions.instrumentName.str.contains('-FS-')]



Best.



Mario

3

Hi Mario!



    Thanks for the response. It worked but without the tilde. Tilde returned everything but the future positions (those with -FS-). Do you have any explaination as to why my method was not working as expected? 

Regards.

4

No, I didn't any trace of your code.



Particulary, I don't like to use the dunder methods, so I simply looked for an easy way to get to the solution.



Best,



Mario