UFuncTypeError: ufunc 'add' did not contain a loop with signature matching types when add-CodePudding

I just want to add element in filtered index. Here's my code, A is dataframe and index is a column

my_input = A["index"]   'a.age'
ML_filtered = ML["index"].isin(my_input)

Here's my error message

UFuncTypeError: ufunc 'add' did not contain a loop with signature matching types (dtype('<U21'), dtype('<U21')) -> dtype('<U21')

What's wrong with the code?

Edit

I try my_input = A["index"] 'a.age'

The error is

TypeError: Cannot broadcast np.ndarray with operand of type <class 'list'>

CodePudding user response：

There is list/array in column A['index'], possible solution is flatten it bySeries.explode :

A = pd.DataFrame({'index':[[1,2],[2,5]]}).applymap(np.array)
print (A)
    index
0  [1, 2]
1  [2, 5]

ML = pd.DataFrame({'index':['1a.age','5a.age', 'tmp']})

my_input = A["index"].explode().astype(str)   'a.age'
ML_filtered = ML["index"].isin(my_input)
print (ML_filtered)
0     True
1     True
2    False
Name: index, dtype: bool