dict= {'a':1,'b':4,'c':2}
sorted(dict.items(),key = lambda x:x[1],reverse = True)

test_data_6=sorted(dict_data.items(),key=operator.itemgetter(1))
test_data_7=sorted(dict_data.items(),key=operator.itemgetter(1),reverse=True)
print(test_data_6) #[(8, 2), (10, 5), (7, 6), (6, 9), (3, 11)]
print(test_data_7) #[(3, 11), (6, 9), (7, 6), (10, 5), (8, 2)]

f = zip(d.keys(), d.values())
c = sorted(f)
print(c)

# 对字典按value排序
a = sorted(d.items(), key=lambda x: x[1], reverse=True)
print(a)

# coding:utf-8

# 作者：上海-悠悠
a = ["a", "b", "a", "c", "a", "c", "b", "d", "e", "c", "a", "c"]

# set集合去重
duixiang = set(a) # 先去重，取出计数对象

# 保存为dict，一一对应
d = {}
for i in duixiang:
  d[i] = a.count(i)


# 对字典按value排序
a = sorted(d.items(), key=lambda x: x[1], reverse=True)
print(a)