数据库的搜索模拟

教学用方案

# # 查找
# # 假设数据库中取出来的数据为以下的内容：
database = [{"name": "zs", "age": 18}, {"name": "zs2", "age": 28}, {"name": "zs", "age": 18}]
# # 查询条件为
cond = {"age": 18, "name":"zs"}
# cond = {"age": 18}
# cond = {"age": 18, "gender":1}
# # 写一套逻辑，可以让database经过一翻处理，得到这样的结果
# res = [{"name": "zs", "age": 18}, {"name": "zs3", "age": 18}]

for data in database:
    print("*"*20)
    print(data)

    # 获得一个又一个的字典
    # data = {"name": "zs", "age": 18}
    # 判断1，条件中的键是否在data字典中
    num = 0  # 计数器,统计有几个符合条件
    cond_num = len(cond)  # 有几个条件
    for k, v in cond.items():
        if k in data and data[k] == v:
            num += 1
            print("{}-{}".format(num, cond_num), data, k,v)
    else:
        if num == cond_num:
            # 判断达到条件的数量与要求的条件数量是否一致
            print(data, '=='*10)

方案

# # 查找
# # 假设数据库中取出来的数据为以下的内容：
database = [{"name": "zs", "age": 18}, {"name": "zs2", "age": 28}, {"name": "zs", "age": 18}]
# # 查询条件为
cond = {"age": 18, "name":"zs"}

for data in database:
    flag = True
    for k, v in cond.items():
        if k in data and data[k] == v:
            # print(data, k, v)
            pass
        else:
            flag = False
    else:
        if flag:
            print(data, '===>')