How can I filter a dataframe by columns for the first time a string is not present?-CodePudding

I'm trying to subset dataframes to exclude the first column without "Unnamed."

Here's an example:

data = {'What is your favorite fruit':['Banana','nan','Banana','nan','nan'],
        'Unnamed:12':['nan', 'Strawberry', 'nan', 'nan', 'nan'],
       'Unnamed:13':['nan', 'nan', 'nan', 'Blueberry', 'Blueberry'],
       'What is your favorite vegetable?':['Carrot','nan','nan','nan','Carrot']}

df = pd.DataFrame(data)

df

What I want is to only subset the data and take the first 3 columns and exclude the new question. In my actual file the number of columns between questions differs, so doing iloc won't work.

CodePudding user response：

To get every column until and including the last column with "Unnamed", try:

>>> df.iloc[:, :max(i for i, c in enumerate(df.columns) if "Unnamed" in c) 1]

  What is your favorite fruit  Unnamed:12 Unnamed:13
0                      Banana         nan        nan
1                         nan  Strawberry        nan
2                      Banana         nan        nan
3                         nan         nan  Blueberry
4                         nan         nan  Blueberry