[vagrant@ansible playbook]$ ansible client1 -i hosts -m ping -vvv
Traceback (most recent call last):
  File "/usr/bin/ansible", line 197, in <module>
    (runner, results) = cli.run(options, args)
  File "/usr/bin/ansible", line 121, in run
    inventory_manager = inventory.Inventory(options.inventory, vault_password=vault_pass)
  File "/usr/lib/python2.7/site-packages/ansible/inventory/__init__.py", line 128, in __init__
    self.parser = InventoryParser(filename=host_list)
  File "/usr/lib/python2.7/site-packages/ansible/inventory/ini.py", line 43, in __init__
    self._parse()
  File "/usr/lib/python2.7/site-packages/ansible/inventory/ini.py", line 47, in _parse
    self._parse_base_groups()
  File "/usr/lib/python2.7/site-packages/ansible/inventory/ini.py", line 108, in _parse_base_groups
    tokens = shlex.split(line)
  File "/usr/lib64/python2.7/shlex.py", line 279, in split
    return list(lex)
  File "/usr/lib64/python2.7/shlex.py", line 269, in next
    token = self.get_token()
  File "/usr/lib64/python2.7/shlex.py", line 96, in get_token
    raw = self.read_token()
  File "/usr/lib64/python2.7/shlex.py", line 191, in read_token
    raise ValueError, "No escaped character"
ValueError: No escaped character