Comment on Processing large files, line by lineparentComments−d0mine13yDon't use `for line in file.readlines():`, do `for line in file:` instead.Don't use `map(writer.writerow, data)`, do `writer.writerows(data)` instead. Use binary mode for csv files in Python 2, use newline='' in Python 3.You forgot to open the first output file in the write mode.
Comments
Don't use `for line in file.readlines():`, do `for line in file:` instead.
Don't use `map(writer.writerow, data)`, do `writer.writerows(data)` instead. Use binary mode for csv files in Python 2, use newline='' in Python 3.
You forgot to open the first output file in the write mode.