Pythonはネストされたリスト辞書をある要素で統合し、lambdaの使用を実現する.

#! /usr/bin/env python
#coding=utf-8

class MergeResource(object):

    def __init__(self, resource_list):

        self.resource_list = resource_list

    def merge_resource(self):

        merge_resource = []
        merge_resource.append(self.resource_list[0])#     
        for dict in self.resource_list[1:]: #      
            k=0
            for item in merge_resource:
                if dict['host'] == item['host']:
                    item['cpu'] += dict['cpu']
                    item['mem'] += dict['mem']
                    break
                else:
                    k=k+1
                if k == len(merge_resource):
                    merge_resource.append(dict)
                    break #       ！！！
        #print 'merge_resource: ', merge_resource

        return merge_resource


if __name__ == '__main__':

    resource_list=[{'host':'compute21', 'cpu':2, 'mem':4},{'host':'compute21', 'cpu':2, 'mem':4},
                 {'host':'compute22', 'cpu':2, 'mem':4},{'host':'compute23', 'cpu':2, 'mem':4},
                 {'host':'compute22', 'cpu':2, 'mem':4},{'host':'compute23', 'cpu':2, 'mem':4},
                 {'host':'compute24', 'cpu':2, 'mem':4}]

    #1、merge  
    maxResourceHost = max(resource_list, key = lambda x: x['cpu'])['host']
    print 'maxResourceHost: ', maxResourceHost
    maxResourceCpu = max(resource_list, key = lambda x: x['cpu'])['cpu']
    print 'maxResourceCpu: ', maxResourceCpu

    #1、merge  
    merge = MergeResource(resource_list)
    merge_resource = merge.merge_resource()

    print 'merge_resource: '
    print merge_resource
    maxResource = max(merge_resource, key = lambda x: x['cpu'])
    print 'maxResource: ', maxResource

    maxResourceCpu = max(merge_resource, key = lambda x: x['cpu'])['cpu']
    print 'maxResourceCpu: ', maxResourceCpu

maxResourceHost:  compute21
maxResourceCpu:  2
merge_resource: 
[{'mem': 8, 'host': 'compute21', 'cpu': 4}, {'mem': 8, 'host': 
'compute22', 'cpu': 4}, {'mem': 8, 'host': 'compute23', 'cpu': 4}, 
{'mem': 4, 'host': 'compute24', 'cpu': 2}]
maxResource:  {'mem': 8, 'host': 'compute21', 'cpu': 4}
maxResourceCpu:  4