# deque双向列表 from collections import deque q = deque(['a', 'b', 'c']) # print(q) # 从右边增加值 q.append('x') q.append('y') # # 从右边删除值 q.pop() q.pop() # 从左边增值 q.appendleft('x') q.appendleft('y') # # 从左边删除 q.popleft() q.popleft() print(q)
# defaultdict from collections import defaultdict # 给字典添加key和对应的数据类型 my_dict = defaultdict(list) # my_dict = defaultdict(str) my_dict['key1'] my_dict['key2'] my_dict['key3'] print(my_dict) # 把小于66的放到key1把大于66的放到key2 values = [11, 22, 33, 44, 55, 77, 88, 99, 90] for val in values: if val > 66: my_dict['key1'].append(val) else: my_dict['key2'].append(val) print(my_dict) # 构建一个字典;字典的key 从1~100，对应的值都是666 # {1：666，2：666，3：666......} # 第一种方法 dic = dict.fromkeys(range(1,101),666) print(dic) # 第二种方法 print({key:666 for key in range(1,101)}) # 第三种方法 def func(): return 666 my_dict = defaultdict(func) for i in range(1, 101): my_dict[i] print(my_dict)
# 统计字符出现的次数并返回一个字典，字典的键为该字符，值为出现的次数 from collections import Counter s1 = '电脑电脑sldfjslffdsaf' # s1 = ['电脑', '电脑', '电脑', '电脑', '书'] c = Counter(s1) print(c) print(c['f']) print(c['d']) print(dict(c))