Python Multiset

gistfile1.txt

import collections
class Multiset(collections.Counter):
    def add(self, elem):
        self[elem] += 1
        
    def remove(self, elem):
        self[elem] -= 1
        if self[elem] == 0:
            del self[elem]
            
    def pop(self):
        k, v = self.popitem()
        if v > 0:
            self[k] = v-1
        return k