Python 基于另一个变量在 dataframe 中生成 dummy

Question

I have dataframe with many variables. I would like to generate a dummy variable based on column 1, for example. If column 1's observation is NaN, then the dummy variable is filled with 0. If column 1' observation is not missing, then the dummy variable is filled with 1. Any ideas? Thanks a lot.

Answer 1

This is the easiest way:

# sample data
import pandas as pd 
import numpy as np
df = pd.DataFrame()
df['sample'] = [1,2,np.nan,4,5,np.nan]

# create dummy column
df['dummy'] = np.where(df['sample'].isna(),0,1)