I need to compute a column where the value is the result of a vectorized operation over other columns:

df["new_col"] = df["col1"] - min(0,df["col2"])

It turned out, however, that I cannot use min as in the above syntax. So, what is the right way to get the min between zero and a given value of pandas column?

you can use numpy.minimum to find the element-wise minimum of an array

import numpy as np
df["new_col"] = df["col1"] - np.minimum(0,df["col2"])