def except_keyword(source, start, keyword):
start = pass_white(source, start)<EOL>kl = len(keyword)  <EOL>if kl + start > len(source):<EOL><INDENT>return None<EOL><DEDENT>if source[start:start + kl] != keyword:<EOL><INDENT>return None<EOL><DEDENT>if kl + start < len(source) and source[start + kl] in IDENTIFIER_PART:<EOL><INDENT>return None<EOL><DEDENT>return start + kl<EOL>
Returns position after keyword if found else None
        Note: skips white space