pythonday4

lst = [1, '哈哈', "吼吼", [1,8,0,"百度"], ("我","叫", "元", "组"), "abc", {"我 叫":"dict字典"},{"我叫集合","集合"}] 

  lst = ["麻花藤", "王剑林", "马芸", "周鸿医", "向华强"]
  print(lst[0])   # 获取第一个元素 
  print(lst[1]) 
  print(lst[2]) 
  lst[3] = "流动强"  # 注意. 列表是可以发生改变的. 这里和字符串不一样 print(lst)  # ['麻花藤', '王剑林林', '马芸', '流动强', '向华强'] 
  s0 = "向华强" 
  s0[1] = "美"  # TypeError: 'str' object does not support item assignment不允许改变 
  print(s0) 
　列表切片:

  lst = ["麻花藤", "王剑林", "马芸", "周鸿医", "向华强"] 
  print(lst[0:3])     # ['麻花藤', '王剑林', '马芸'] 
  print(lst[:3])      # ['麻花藤', '王剑林', '马芸']
  print(lst[1::2])    # ['王剑林林', '周鸿医'] 也有步长 
  print(lst[2::-1])   # ['马芸', '王剑林', '麻花藤'] 也可以倒着取 print(lst[-1:-3:-2])    # 倒着带步长 

二. 列表的增删改查

  1.增,注意, list和str是不一样的. lst可以发生改变. 所以直接就在原来的对象上进行了操作

  lst = ["麻花藤", "林林俊杰", "周润发", "周芷若"] 
  print(lst)
  lst.append("wusir") 
  print(lst)



  lst = []
  while True:
    content = input("请输入你要录入的员工信息, 输入Q退出:")
    if content.upper() == 'Q':
        break
    lst.append(content)
  print(lst)



  lst = ["麻花藤", "张德忠", "孔德福"]
  lst.insert(1, "刘德华")    # 在1的位置插入刘德华. 原来的元素向后移动一位
  print(lst) 



# 迭代添加
  lst = ["王志文", "张一山", "苦?无涯"]
  lst.extend(["麻花藤", "麻花不疼"])
  print(lst) 

  lst = ["麻花藤", "王剑林林", "李李嘉诚", "王富贵"] 
  print(lst) 
  deleted = lst.pop()         # 默认删除最后一个 
  print("被删除的项", deleted) 
  print(lst) 
  el = lst.pop(2)     # 删除2号元素 ,删除指定索引表示的项
  print(el) 
  print(lst)




  lst.remove("麻花藤")   # 删除指定元素,指定元素重复时,删除第一个,只能删一个
  print(lst) 
  # lst.remove("哈哈")    # 删除不存在的元素会报错 
  # print(lst) 





  lst.clear()     # 清空list 
  print(lst) 

  del lst[1:3] 
  print(lst)

  lst = ["太白", "太黑", "五色", "银王", "日天"] 
  lst[1] = "太污"   # 把1号元素修改成太污 
  print(lst)
  lst[1:4:3] = ["麻花藤", "哇靠"]# 如果步长不是1, 要注意. 元素的数, 例:步长为3时,指的是原列表指定每3个元素中的第一个元素修改,步长过大,要修改的元素不能全部修改则会报错.
  print(lst) 
  lst[1:4] = ["李嘉诚个龟儿子"]  # 如果切片没有步长或者步长是1. 则不用关心个数 
  print(lst)

  lst=["太白", "太黑",1,2, ]
  for el in lst:
     print(el)

  lst = ["太白", "太黑", "五色", "银王", "日天", "太白"] 
  c = lst.count("太白")     # 查询太白出现的次数 
  print(c) 
  lst = [1, 11, 22, 2] 
  lst.sort()          # 排序. 默认升序 
  print(lst) 
  lst.sort(reverse=True)  # 降序 
  print(lst)




  lst = ["太白", "太黑", "五色", "银王", "日天", "太白"] 
  print(lst) 
  lst.reverse() 
  print(lst)




  l = len(lst)    # 列表的长度 print(l) 

  lst = [1, "太白", "wusir", ["马虎疼", ["可乐"], "王剑林"]] 
  # 找到wusir 
  print(lst[2]) 
  # 找到太白和wusir 
  print(lst[1:3]) 
  # 找到太白的白字 
  print(lst[1][1]) 
  # 将wusir拿到. 然后首字母大写. 再扔回去 
  s = lst[2] 
  s = s.capitalize() 
  lst[2] = s print(lst) 
  # 简写
   lst[2] = lst[2].capitalize() 
  print(lst) 
  # 把太白换成太黑 
  lst[1] = lst[1].replace("白", "黑") 
  print(lst) 
  # 把马虎疼换成马化疼 
  lst[3][0] = lst[3][0].replace("虎", "化") 
  print(lst[3][0]) 
  lst[3][1].append("雪碧") 
  print(lst)

  tu = (1, "太白", "李白", "太黑", "怎么黑")
  print(tu) 
  print(tu[0]) 
  print(tu[2]) 
  print(tu[2:5])  # 切片之后还是元组 
  # for循环遍历元组 
  for el in tu:
      print(el) 
  # 尝试修改元组 
  # tu[1] = "马虎疼"  # 报错 'tuple' object does not support item assignment 
  tu = (1, "哈哈", [], "呵呵") 
  # tu[2] = ["fdsaf"]   # 这么改不行 
  tu[2].append("麻花藤")  # 可以改了.没报错 第三个元素为列表,可以更改
  tu[2].append("王剑林林") 
  print(tu)

      for num in range(10):   #默认从0开始到10结束不包括10.
            print(num) 

      for num in range(1, 10, 2):   #从1开始到10结束,不包括10,步长为2.
            print(num) 

      for num in range(10, 1, -2):    # 反着来, 和切片一样 
           print(num)