Pandas Lambda Function with Nan Support

Question

I am trying to write a lambda function in Pandas that checks to see if Col1 is a Nan and if so, uses another column\'s data. I have having trouble getting code (below) to c

Answer 1

You need to use np.nan()

#import numpy as np
df2=df.apply(lambda x: 2 if np.isnan(x['Col1']) else 1, axis=1)   

df2
Out[1307]: 
0    1
1    1
2    1
3    2
dtype: int64