Python IF , or logic returning wrong results

Question

I have a table with the following information

No of transactions	GST	Item cost GST inclusive
1	0	0.5

I wish to include an additonal column with the following logic

def incl(s):
    if ((s['No of Transactions'] ==0) & (s['GST'] ==0)):
        return s['Item Cost GST inclusive']
    else:
        return s['Item Cost GST inclusive']*0.9

df2['Item Cost GST exclusive'] = df2.apply(incl, axis=1)

I am getting the following table

No of transactions	GST	Item cost GST inclusive	Item cost GST exclusive
1	0	0.5	0.45

Logically when there is no GST, item cost GST inclusive does not get multlplied by 0.9, because there is no point in triggering the condition. Also generally in cases where 'no of transaction' is 0, there is no item cost at all.

I was expecting the following table

No of transactions	GST	Item cost GST inclusive	Item cost GST exclusive
1	0	0.5	0.5

I am not sure what went wrong in the logic. I am sure the logic is wrong. Please help.

I will appreciate any kind suggestions please.

Because `'No of transactions'` is not 0 but `'GST'` is 0, it does not meet the if condition, so you get 0.45. Is there a problem? — Mechanic Pig, Jun 17 '22 at 06:44
Logically when there is no GST, item cost GST exclusive does not get multlplied by 0.9, because there is no point in triggering the condition. Also generally in cases where no of transaction is 0, there is no item cost at all. What is the mistake in the logic guys? — Mihan, Jun 17 '22 at 07:04
@Mechanic pig, I am slightly confused. I think or will not do the trick and 'and' is taking the first condition only. The correct condition Thretically, fisrt look into no if transaction , and if it is not 0 than look into GST to trigger the calculation. — Mihan, Jun 17 '22 at 07:10
@Mihan I think what you need is `or` instead of `and`. The former only requires one of the two conditions to be true, and the latter requires both to be true. — Mechanic Pig, Jun 17 '22 at 07:12

rohith santosh · Accepted Answer · 2023-03-02T06:53:09.843

0

def incl(s):
    if ((s['No of Transactions'] ==0) or (s['GST'] ==0)):
        return s['Item Cost GST inclusive']
    else:
        return s['Item Cost GST inclusive']*0.9

df2['Item Cost GST exclusive'] = df2.apply(incl, axis=1)

This should do it.

edited Mar 02 '23 at 06:53

answered Jun 17 '22 at 06:40

rohith santosh

28
6
23

might get a better idea, have a look at this https://www.geeksforgeeks.org/difference-between-and-and-in-python/#:~:text=and%20is%20a%20Logical%20AND,otherwise%20True%20when%20using%20logically. – rohith santosh Jun 17 '22 at 06:41
That did not work. – Mihan Jun 17 '22 at 07:01
could you share the data that you're working on? – rohith santosh Jun 17 '22 at 15:58
1

my appologies. The data is confidential. But the problem is solved with 'or' as '@Mechanic suggested. Thank you so much for helping me out. – Mihan Jun 19 '22 at 02:15

Python IF , or logic returning wrong results

1 Answers1