pandas factorize

# function to obtain Categorical Features
def _get_categorical_features(df):
    feats = [col for col in list(df.columns) if df[col].dtype == 'object']
    return feats

# function to factorize categorical features
def _factorize_categoricals(df, cats):
    for col in cats:
        df[col], _ = pd.factorize(df[col])
    return df