from time import asctime

class FormatError(Exception):
    logfile = 'parser-errors.txt'
    def __init__(self, line, file):
        self.line = line
        self.file = file
    def logerror(self):
        with open(self.logfile, 'a') as log:
            print(f'Error at: {self.file} #{self.line} [{asctime()}]', file=log)

def parser(file):
    # Parse a file here...
    raise FormatError(line=62, file=file)

if __name__ == '__main__':
    try:
        parser('code.py')
    except FormatError as exc:
        exc.logerror()