# # 字符串 # my_str = "tom and jerry" # value = my_str[2] # value1 = my_str[-12] # print(f"字符串中取出下标为2的字符为{value}，取出下标为-12的字符为{value1}") # # 字符串常用方法index # value2 = my_str.index("tom") # print(f"字符串查找tom，其起始下标为{value2}") # # 字符串常用方法，replace # new_my_str = my_str.replace("jerry", "xi_mi") # print(new_my_str) # print(my_str) # # 字符串常用方法 split # my_str_list = my_str.split(" ") # print(f"{my_str_list}") # # 字符串规整操作 strip # my_str1 = " hello world " # new_my_str1 = my_str1.strip() # print(f"{new_my_str1}") # my_str2 = "12hello 12world21" # new_my_str2 = my_str2.strip("12") # print(f"字符串{my_str2}被strip（12）后结果为{new_my_str2}") # # 字符串中某字符串出现的次数，count # count = my_str.count("a") # print(f"{count}") # # 统计字符串长度 len() # len1 = len(my_str) # print(f"{len1}") # 字符串遍历 # index = 0 # my_str = "Good morning" # while index < len(my_str): # element = my_str[index] # index += 1 # print(f"{element}") # my_str1 = "Good afternoon" # for element in my_str1: # print(f"{element}") # # 序列切片 # # 对list切片，从1开始，4结束，步长1 # my_list = [0, 1, 2, 3, 4, 5, 6] # result1 = my_list[1:4] # 步长为1，可省略 # print(f"{result1}") # # 从头开始，到最后结束，步长为2 # result2 = my_list[::2] # print(f"{result2}") # # 对str切片，从头开始到最后结束，步长-1 # my_str = "01234567" # result3 = my_str[::-1] # print(f"{result3}") # # 对元组切片，从头开始，到尾结束，步长-2 # my_tuple=(0,1,2,3,4,5,6,7) # result4=my_tuple[::-2] # print(f"{result4}") # # 集合 # my_set = {"tom", "jerry", "python", "element", "tom"} # my_set_empty = set() # print(f"me_set的内容是：{my_set},类型是{type(my_set)}") # print(f"me_set_empty的内容是：{my_set_empty},类型是{type(my_set_empty)}") # # 添加元素 # my_set.add("heima") # my_set.add("python") # print(f"{my_set}") # # 移除元素 # my_set.remove("jerry") # print(f"{my_set}") # # 随机取出一个元素 # element = my_set.pop() # 此操作为随机取出 # print(f"{my_set}") # # 清空集合 # result= my_set.clear() # print(f"{my_set}") # # 取出两个集合的差集 # set1 = {1, 2, 3} # set2 = {1, 4, 6} # set3 = set1.difference(set2) # print(set3) # print(set1) # # 消除差集 # set1.difference_update(set2) # print(f"消除差集后，集合1的结果是{set1}") # print(f"消除差集后，集合2的结果是{set2}") # 只对集合1消除，集合2不变 # 两集合合并 # set4=set1.union(set2) # print(f"两集和合并结果为{set4}") # print(f"合并后集合1为{set1}") # print(f"合并后集合2为{set2}")#合并后原集合不变 # #集合统计 # num=len(set4) # print(num) # 集合的遍历 # 集合不支持下标索引，所以不能用while循环 # set1 = {1, 2,3,4,5,6} # for element in set1: # print(f"集合的元素有{element}") # # 字典 # my_dict = {"王力宏": 99, "汤姆": 88, "林俊杰": 77} # my_dict2 = dict() # my_dict2={} # print(f"my_dict的内容是{my_dict},类型 为{type(my_dict)}") # print(f"my_dict2的内容是{my_dict2},类型 为{type(my_dict2)}") # # 定义重复字典 # my_dict1 = {"王力宏": 99, "王力宏": 88} # print(f"重复定义的结果{my_dict1}") # 从字典基于key获取value # result = my_dict["王力宏"] # result1 = my_dict["林俊杰"] # print(f"王力宏的考试分数为：{result}") # print(f"王力宏的考试分数为：{result1}") # # 字典嵌套 # stu_score_dict = { # "王力宏":{ # "语文":77, # "数学":88, # "英语":66, # }, # "周杰伦":{ # "语文":99, # "数学":99, # "英语":99, # } # } # score = stu_score_dict["周杰伦"]["语文"] # print(f"周杰伦的语文信息为{score}") # # 字典常用操作 # my_dict = {"周杰伦": 33, "林俊杰": 24, "张学友": 88} # my_dict["张信哲"] = 32 # print(f"更新后my_dict结果是{my_dict}") # my_dict["周杰伦"] = 38 # print(f"更新后my_dict结果是{my_dict}") # # 删除元素 # score = my_dict.pop("周杰伦") # print(f"字典中被删除了一个元素，结果为{my_dict},周杰伦的考试分数为{score}") # my_dict.clear() # print(f"字典被清空了，内容是{my_dict}") # 获取全部的key my_dict = {"周杰伦": 33, "林俊杰": 24, "张学友": 88} keys = my_dict.keys() print(f"字典的全部key是{keys}") # 遍历字典 # 方式1通过获取全部的key来完成遍历 for key in my_dict.keys(): print(f"字典的key是：{key}") print(f"字典的value是：{my_dict[key]}") # 方式2 直接对字典进行for循环,每次循环都是直接得到key for key in my_dict: print(f"字典的key是：{key}") print(f"字典的value是：{my_dict[key]}") # 统计字典的数量，len（） num = len(my_dict) print(f"字典中的key数量为{num}")