将功能应用于数据框中的特定行

Question

I have a dataframe of which I want to clean up a specific row, in this case the first row. I have written a function in which I believe will return the string if the regex is matched.

def clean_cells(string):
    if '201' in string:
        return re.findall('201[0-9]', string)[0]
    else:
        return string

I want to apply this function to the first row in the dataframe then replace the first row with the cleaned up version then contatenate the rest of the original dataframe.

I have tried:

df = df.iloc[[0]].apply(clean_cells)

Answer 1

Select first row by position and all columns with : and assign back:

df.iloc[0, :] = df.iloc[0, :].apply(clean_cells)

Another solution:

df.iloc[0] = df.iloc[0].apply(clean_cells)

Answer 2

仅替换选定的行，而不是整个DataFrame：

df.iloc[[0]] = df.iloc[[0]].apply(clean_cells)