Pandas DF column values get changed but to_csv shows old values

Question

I'm trying to convert some excel files into csv. The follow code worked fine for .xlsx type files but is not working for .xlsm type files:

for i, row in df.iterrows():
    if(row[0] == 'X'): row[0] = 'Y'

csv_file = df.to_csv(name, index=None, header=True)

The df columns get changed but the output to the csv file remains as 'X'

Answer 1

I'm surprised your solution worked at all; I believe iterrows returns copies of the rows, so modifying those copies shouldn't do anything. A better solution would be to use .replace:

df.iloc[:, 0] = df.iloc[:, 0].replace('X', 'Y')

Or, if you know the name of the column you want to replace X with Y in, use it:

df['column name'] = df['column name'].replace('X', 'Y')