从另一列pandas df分配值的有效方法

您可以使用：

def f(x):    #get unique days    u = x['Day'].unique()    #mapping dictionary    d = dict(zip(u, np.arange(len(u)) // 3 + 1))    x['new'] = x['Day'].map(d)    return xdf = df.groupby('Location', sort=False).apply(f)#add Location columns = df['new'].astype(str) + df['Location']#encoding by factorizedf['new'] = pd.Series(pd.factorize(s)[0] + 1).map(str).radd('C')print (df)      Day Location new0     Mon     Home  C11    Tues     Home  C12     Wed     Away  C23     Wed     Home  C14   Thurs     Away  C25   Thurs     Home  C36     Fri     Home  C37     Mon     Home  C18     Sat     Home  C39     Fri     Away  C210    Sun     Home  C4