python随记

a = {"a":1, "b":5, "c":3}
b = sorted(a.items(), key=lambda x:x[1], reverse=True)    #sorted用法
print(b)

print(min(zip(a.values(), a.keys()))) #找到字典中哪个值最大

print(max(a.values())) #找到字典中哪个值最大

print(max(a, key=lambda x:a[x]))        #找到字典里最大值对应的key

from collections import deque
import heapq
from collections import Counter
from operator import itemgetter
a = {"a":1, "b":5, "c":3}
b = {"e":2, "b":5, "d":4}
# b = sorted(a.items(), key=lambda x:x[1], reverse=True)    #sorted用法
# print(b)

# print(min(zip(a.values(), a.keys()))) #找到字典中哪个值最大

# print(max(a.values()))
#
# print(max(a, key=lambda x:a[x]))        #找到字典里最大值对应的key

# print(a.keys() & b.keys())      #找出二个字典中具有相同的 key
# print(a.items() & b.items())    #找出二个字典中key，value都相同的项

# a = [1,2,3,4]
# b,*e,m = a
# print(m)

# c = deque(maxlen=3)     #创建一个固定长度的列表
# c.append(1)
# c.append(2)
# c.append(3)
# c.append(4)
# print(c)
#
# c.appendleft(5)  #左边添加一个
# print(c)
# c.popleft()      #左边删除第一个
# print(c)

# nums = [1,2,5,0,8,3,5,2,0,8,9,1]
# # print(heapq.nlargest(3, nums))      # 找到最大的三个元素
# # print(heapq.nsmallest(3, nums))     #找到最小的三个元素

# nums = [(1,5),(2,0),(8,9),(0,6)]
# print(heapq.nlargest(2, nums, key=lambda x:x[0]))       #字典也同样可以操作

# a = {"a":12, "b":33, "c":11}
#
# print(min(zip(a.values(), a.keys())))       #获取字典 value 最小的值
# b = sorted(zip(a.values(), a.keys()))       #字典 value 排序
#
# print({key:value for value,key in b})
#
# print({value:key for key,value in a.items()})       #字典 key value 翻转


# words = ['look', 'like', 'he', 'look', 'he', 'look']        #实现单词出现次数统计并排序
# word_counts = Counter(words)
# print(word_counts)
# print(word_counts.most_common(2))       #如果指定为 2 ，  就获取出现最多的 2 个单词
# print(word_counts['look'])


m = {'look': 3, 'he': 2, 'like': 1}
m1 = Counter(m)

m2 = {'look': 1, 'he': 1, 'like': 1}
m3 = Counter(m2)
print(m1 + m3)      #通过 Counter 可以对字典相同的value进行数据计算

b = [
    {"a":123, "b":333, "c":53},
    {"a":12, "b":3393, "c":53},
    {"a":12, "b":33343, "c":53},
]

print(sorted(b, key=itemgetter('a'), reverse=True))     #排序列表字典

print(sorted(b, key=lambda x:(x['a'], x['b'])))