I recently discovered pandas \"assign\" method which I find very elegant. My issue is that the name of the new column is assigned as keyword, so it cannot have spaces or das
You can pass the keyword arguments to assign as a dictionary, like so:
kwargs = {"ln(A)" : lambda x: np.log(x.A)}
df.assign(**kwargs)
A B ln(A)
0 1 0.500033 0.000000
1 2 -0.392229 0.693147
2 3 0.385512 1.098612
3 4 -0.029816 1.386294
4 5 -2.386748 1.609438
5 6 -1.828487 1.791759
6 7 0.096117 1.945910
7 8 -2.867469 2.079442
8 9 -0.731787 2.197225
9 10 -0.686110 2.302585