--- start config.yaml ---
main:
       a: 1
       b: 2
next:
       c: 3
       d: 4
--- end config.yaml ---

import yaml

config = yaml.load(open('config.yaml', 'r'))
print config
{main:{a:1, b:2}, next:{c:3, d:4}}

config.dump(config, open('config2.yaml', 'w'))

--- start config2.yaml ---
main: {a:1, b:2}
next: {c:3, d:4}
--- end config2.yaml ---