A netrc instance or subclass instance encapsulates data from
a netrc file. The initialization argument, if present, specifies the
file to parse. If no argument is given, the file .netrc in the
user's home directory will be read. Parse errors will raise
NetrcParseError with diagnostic information including the
file name, line number, and terminating token.
Exception raised by the netrc class when syntactical errors
are encountered in source text. Instances of this exception provide
three interesting attributes: msg is a textual explanation
of the error, filename is the name of the source file, and
lineno gives the line number on which the error was found.