Day2

完成： 1、学习python全部内容 2、用python完成leecode每日一题

#转成字典 from collections import Counter colors = ['red', 'green', 'blue', 'yellow', 'yellow', 'blue', 'blue'] c = Counter(colors) print(c) print(dict(c)) #转成字典

#字符串翻转 string = 'leetcode' print(string[::-1])

#字典遍历 cnt = {1:4, 2:3} #遍历键值对 for x in cnt.items(): print(x) #遍历键 for x in cnt.keys(): print(x) #遍历值 for x in cnt.values(): print(x)

#列表初始化 length = 5 #第一种 li=[0]*length print(li) #第二种 li = [0 for i in range(length)] print(li) #第三种 li = [[0] * 3 for i in range(4)] print(li)

#有序序列的插入和查找 import bisect a = [1,2,2,5,8] position = bisect.bisect(a, 7) #二分查找 print(position) bisect.insort(a, 4) print(a) print(bisect.bisect_left(a, 2)) print(bisect.bisect_right(a, 2))

#取字典最大value值对于的key num = [1, 2, 2, 2, 3, 4, 4] cnt = Counter(num) print(cnt) print(cnt.get(4)) print(max(cnt.keys(), key=cnt.get))