def validate(fmt, stri):
try:<EOL><INDENT>parse(fmt, stri)<EOL>return True<EOL><DEDENT>except ValueError:<EOL><INDENT>return False<EOL><DEDENT>
Validates that string *stri* is parsable and therefore complies with
the format string, *fmt*.  Useful for filtering string, or to 
check if string if compatible before passing the string to the
parser function.