oracle:
    host: 192.168.0.1
    port: 1521
    user: p2
    passwd: ****
    db: tlp
    NLS_LANG: American_America.AL32UTF8
LU:
    430:
        mail: 1@1t.ru
    413:
        mail: 2@2t.ru
START_DATE: 01.01.2015
END_DATE: 31.12.2015

import yaml
with open("config.yml", 'r') as ymlfile:
    cfg = yaml.load(ymlfile)
print cfg['LU']

[430, 413]

>>> import yaml
>>> import io
>>> 
>>> fp = io.StringIO(
... """
... oracle:
...     host: 192.168.0.1
...     port: 1521
...     user: p2
...     passwd: xxxx
...     db: tlp
...     NLS_LANG: American_America.AL32UTF8
... LU:
...     430:
...         mail: 1@1t.ru
...     413:
...         mail: 2@2t.ru
... START_DATE: 01.01.2015
... END_DATE: 31.12.2015
... """
... )
>>> 
>>> cfg = yaml.load(fp)
>>>
>>> lu = cfg['LU']
>>> lu[430], lu[413]
({'mail': '1@1t.ru'}, {'mail': '2@2t.ru'})
>>>