Return names which exist in second dataframe-CodePudding

I am currently trying to populate a dropdown list with labels that need to exist in a second dataframe, currently, the below is returning a True and False option:

[{'label': i, 'value': i} for i in sorted(dff.Opp.isin(df2['Name']).unique().astype(str))],

any advice on what needs to be changed?

EDIT: DataFrame examples:

df1:
0  Opp
1  Test2
2  Test4
3  Test6
4  Test7

df2:
0  Name
1  Test1
2  Test2
3  Test3
4  Test4
5  Test5

Expected outcome: dropdown would be populated with Test2 and Test4 as they are in both dataframes

CodePudding user response：

I assume that you're currently working with pandas. I tried to reproduce your issue with the code below. From the official document,

pandas.Series.isin returns Series of booleans indicating if each element is in values.

you need to filter values in the Series with loc function before calling .unique()

dff = pd.DataFrame(data={"Opp": ["a", "b", "c", "d", "e"]})
df2 = pd.DataFrame(data={"Name": ["a", "e"]})

dff.loc[dff['Opp'].isin(df2['Name']), 'Opp'].unique()

# Output:
# array(['a', 'e'], dtype=object)

Solution

[{'label': i, 'value': i} for i in sorted(dff.loc[dff['Opp'].isin(df2['Name']), 'Opp'].unique())]

# Output:
# [{'label': 'a', 'value': 'a'}, {'label': 'e', 'value': 'e'}]