2021年3月17日

时间:2个小时左右

代码:100行左右

博客:1

知识点:Python的高级数据类型

# 高级数据类型 list 列表，tuple 元组，dict 字典，set 集合
# 列表 list
num_list = [12, 34, 45, 56, 78]
print(type(num_list))
print(num_list)
print(len(num_list))
print(dir(num_list))
# 对列表进行操作：增删改查

# 查询
print(num_list.index(12))  # 查询某个元素的下标
print(num_list[3])

# 添加
num_list.insert(0, "思瑜")
print(num_list)
num_list.append(1.79)  # 追加
print(num_list)
list1 = [88, 99, 78]
# extend 列表的合并
num_list.extend(list1)
print(num_list)

# 修改
num_list[1] = "小明"
print(num_list)

# 删除
num_list.remove("小明")  # remove放的是数
print(num_list)
# pop弹出最后一个元素
print(num_list.pop(3))
print(num_list)

# count 查看某一元素在列表中出现的次数
print(num_list.count(78))

num1 = [12, 3, 45, 23, 90, 3]
print(num1)
num1.sort(reverse=False)
print(num1)

# 遍历

for item in num_list:
    print(item)

# 元组 特点：不能修改 优点：确保数据的安全，mysql数据库读出来的数据都是tuple类型

num_tuple = (12, 13, 45)
print(type(num_tuple))
print(len(num_tuple))
print(dir(num_tuple))

print(num_tuple.index(13))
print(num_tuple.count(12))

# 列表和元组之间的转换
# 把元组转换为list
list2 = list(num_tuple)
print(type(list2))
print(list2)

# 再次转换为tuple
tup1 = tuple(list2)
print(tup1)
print(type(list2))
print(list2)

# 字典 dict:是以键值对的方式存储数据
dict_info = {
    "name": "张三",
    "age": "18",
    "score": "90",
    "classes": "python"
}

print(dict_info)
print(type(dict_info))
print(dir(dict_info))
# 增删改查

# 增
dict_info['height'] = 1.75
print(dict_info)

# 修改
dict_info["age"] = 20
print(dict_info)

# 删除
print(dict_info.pop("age"))  # 根据key删除
print(dict_info.popitem())
print(dict_info)
print(dict_info.get("age"))
print(dict_info.keys())
print(dict_info.values())

# 对字典进行遍历
for key in dict_info.keys():
    print(key)
    print(dict_info[key])

for value in dict_info.values():  # 只取值
    print(value)

for item in dict_info.items():
    print(item)