我有一个带有多索引索引和列的空数据框。我还有二级索引的坐标字符串列表。因为我的所有二级索引都是唯一的，所以我希望找到包含字符串列表的坐标和输入值。看一下下面的例子
df=
DNA Cat2 ....
Item A B C D E F F H I J
DNA Item
Cat2 A 0 0 0 0 0 0 0 0 0 0
B 0 0 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0
....
str_cord = [(A,B),(A,H),(A,I),(B,H),(B,I),(H,I)]
#and my output should be like below.
df_result=
DNA Cat2 ....
Item A B C D E F F H I J
DNA Item
Cat2 A 0 1 0 0 0 0 0 1 1 0
B 0 0 0 0 0 0 0 1 1 0
C 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0
H 0 0 0 0 0 0 0 0 1 0
....
它看起来有点复杂，但我想要做的就是使用我的str_cord [0]作为df_result的坐标。我尝试使用.loc，但似乎我需要输入1级索引。我正在寻找我不必输入多索引level1并找到level2字符串的坐标的方式。希望它有意义，并提前感谢！ （哦，数据本身非常大，尽可能高效）
答案 0 :(得分：1)
您可以使用：
for i, j in str_cord:
idx = pd.IndexSlice
df.loc[idx[:, i], idx[:, j]] = 1
样品：
L = list('ABCDEFGHIJ')
mux = pd.MultiIndex.from_product([['Cat1','Cat2'], L])
df = pd.DataFrame(0, index=mux, columns=mux)
print (df)
Cat1 Cat2
A B C D E F G H I J A B C D E F G H I J
Cat1 A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
B 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
J 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Cat2 A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
B 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
J 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
str_cord = [('A','B'),('A','H'),('A','I'),('B','H'),('B','I'),('H','I')]
for i, j in str_cord:
idx = pd.IndexSlice
df.loc[idx[:, i], idx[:, j]] = 1
print (df)
Cat1 Cat2
A B C D E F G H I J A B C D E F G H I J
Cat1 A 0 1 0 0 0 0 0 1 1 0 0 1 0 0 0 0 0 1 1 0
B 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0
C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
H 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
J 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Cat2 A 0 1 0 0 0 0 0 1 1 0 0 1 0 0 0 0 0 1 1 0
B 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0
C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
H 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
J 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0