在两列上有条件的python值

Question

I have the following dataset:

id  Rank   condition1    condition2  result 
1    2      50           0            0  
1    2      50           0            0
2    55     50           1            0
2    55     50           1            0

I want to make the result column to 1 conditional on the two columns condition 1 and condition 2.

The Result should become 1 if rank <= condition 1 AND if condition2 = 0

id  Rank   condition1    condition2  result 
1    2      50           0            1  
1    2      50           0            1
2    55     50           1            0
2    55     50           1            0

I have tried the following code but get "invalid syntax".

df["result"][df[condition2] = 0 & df["Rank"]<= df["condition1"]] = 1

Can somebody help me in finding the error? I know how to make this command conditional on one condition, but I do not know how to incorporate the second condition with the AND command.

Answer 1

You need to use == for equality checks, the single = is for assignments not for comparisons:

df["result"][(df['condition2'] == 0) & (df["Rank"]<= df["condition1"])] = 1

You also forgot the ' for condition2 and I included some parenthesis to seperate the conditions because & has higher precedence than == or <= .

Pandas also provides methods for comparisons ( eq and le in this case), so you could also use:

df["result"][df['condition2'].eq(0) & df['Rank'].le(df['condition1'])] = 1