def validate_path_exists(s):
 if os.path.exists(s):
  return s
 else:
  raise RuntimeError(('"%s" should be a path but it does not exist' % s))

def validate_path_exists ( s ) : if os . path . exists ( s ) : return s else : raise RuntimeError ( ( '"%s" should be a path but it does not exist' % s ) )
if s is a path .