【python + flask】字典字段对模型字段的自动赋值，抽象编程思维培养，框架能力

场景：

客户端提交上来的数据

# @Time      :2024-2024/2/27-10:40
# @Author    :Justin
# @Email     :514422868@qq.com
# @file      :demo1.py
# @Software  :FisherBook# class A():
#     def __enter__(self):
#         print("I am enter!")
#         # 这里必须要return self 否则 as b中报错
#         return self
#
#     def __exit__(self, exc_type, exc_val, exc_tb):
#         print("i am exit")
#
#     def query(self):
#         print("i am query")
#
#
# a = A()
# a.query()
# with A() as b:
#     b.query()
#
#
# class Sample:
#     def __enter__(self):
#         print("in enter!")
#         return "aaa"
#
#     def __exit__(self, exc_type, exc_val, exc_tb):
#         print("in exit")
#
#     @staticmethod
#     def get_sample():
#         return Sample()
#
#
# s = Sample()
# with s.get_sample() as sample:
#     print("sample:", sample)
from contextlib import contextmanager# @contextmanager
import tracebackclass MyResource():def __enter__(self):print("i am enter")return selfdef __exit__(self, exc_type, exc_val, exc_tb):print("i am exit")if exc_type:print(exc_type, exc_val, exc_tb)print(traceback.format_exc())raise exc_valdef query(self, data):print("i am query data")with MyResource() as r:r.query(data=[])print("-------------")
from contextlib import contextmanager@contextmanager
def make_myresource():print("connect to resource!")yield MyResource()print("close resource connection!")try:with make_myresource() as r:try:r.query([])except Exception as e:print(traceback.format_exc())
except Exception as e:print(e)from contextlib import contextmanager@contextmanager
def book_mark():print("《", end="")yieldprint("》", end="")with book_mark():print("且将生活一饮而尽", end="")
print("-----")class C:@contextmanagerdef ccc(self):print("1111")yieldprint("33333")c = C()
with c.ccc():print("2222")print("==========")# hasattr()
# setattr()
class D():id = Nonename = Nonedef __init__(self, no=0):self.no = no# 类属性也可以
d = D()
print(hasattr(d, "id"), hasattr(d, "age"), hasattr(d, "no"))param = {"name": "张三","age": 18,"gender": 1,"class_no": 11# 等等很多属性
}class Student():# __slots__ = "name", "age", "gender", "class_no", "__dict__"passstudent = Student()
student.name = param["name"]
student.age = param["age"]
student.gender = param["gender"]
student.class_no = param["class_no"]print(student.age, student.__dict__, student.__dir__())
# var的做法只能将构造函数里面的属性转成字典，而__dict__则范围更广
my_dict = vars(student)
print(my_dict)class Student2():name = Noneage = Nonegender = Noneclass_no = Nonedef setattrs(self, attrs_dict: dict):for key, value in attrs_dict.items():if hasattr(self, key):setattr(self, key, value)student2 = Student2()
student2.setattrs(param)
print(vars(student2))

vars 可以将定义过的对象属性或者类属性，还原成字典。
加上slots的则不可以。
hasattr和setattr可以配对使用
也可以用内置的__setattr__(self, key, value)来处理。

2.统一处理

比如有些字段，时间则需要统一转换，或者自增id在使用时则需要隐藏，

class Student2():name = Noneage = Nonegender = Noneclass_no = Nonedef __init__(self):self.create_time = int(datetime.now.timestamp())def setattrs(self, attrs_dict: dict):for key, value in attrs_dict.items():if hasattr(self, key) and key != "id":setattr(self, key, value)