Traceback (most recent call last):

 "<string>", line 1, in <module>

 "/usr/local/lib/python2.7/site-packages/yaml/__init__.py", line 71, in load
return loader.get_single_data()

 "/usr/local/lib/python2.7/site-packages/yaml/constructor.py", line 37, in get_single_data
node = self.get_single_node()

 "/usr/local/lib/python2.7/site-packages/yaml/composer.py", line 39, in get_single_node
if not self.check_event(StreamEndEvent):

 "/usr/local/lib/python2.7/site-packages/yaml/parser.py", line 98, in check_event
self.current_event = self.state()

 "/usr/local/lib/python2.7/site-packages/yaml/parser.py", line 174, in parse_document_start
self.peek_token().start_mark)yaml.parser.ParserError: expected '<document start>', but found '<scalar>'
Traceback (most recent call last):


 "<stdin>", line 1, in <module>


 "<stdin>", line 1, in <listcomp>
ValueError: Integers to negative integer powers are not allowed.
