Used to merge several compose file properly (might works for other YAML file)

compose_merger.py

import sys
import yaml

def merge(x, y):
    if isinstance(x, dict) and isinstance(y, dict):
        for k,v in y.iteritems():
            if k not in x:
                x[k] = v
            else:
                x[k] = merge(x[k], v)
    return x

print "Mergin' {} with {} and write results in {}".format(sys.argv[1], sys.argv[2], sys.argv[3])

yaml.dump(merge(yaml.load(open(sys.argv[1], 'r')),
                yaml.load(open(sys.argv[2], 'r'))),
          open(sys.argv[3], 'w'))