df = pd.DataFrame(np.random.randint(0,100,size=(3, 4)), columns=list('ABCD')) df['_index'] = 1 pd.merge(df[['_index', 'A']], df[['_index','B']], how='outer', on='_index') df.drop(columns=['_index'], inplace=True) stackoverflow.com

In [1]: import pandas as pd In [2]: s = pd.Series(['a', 'b', 'a', 'c']) In [3]: s Out[3]: 0 a 1 b 2 a 3 c dtype: object In [4]: dummies = pd.get_dummies(s) In [5]: dummies Out[5]: a b c 0 1 0 0 1 0 1 0 2 1 0 0 3 0 0 1 In [6]: s2 = dummies.…