标签：rmi time field class res 结果 参数 item png
实现python对象和原生数据相互转换，如实现object -> dict， objects -> list，string -> dict, string -> list等的转换功能，另外它还停工了非常丰富的数据类型转换和校验API。
pip install marshmallow
调用load事件（loads，dump，dumps）
from marshmallow import fields, post_load, Schema data = [{"name": "lin", "age": 23}, {"name": "fang", "age": 20}] class User(object): def __init__(self, name, age): self.name = name self.age = age class UserSchema(Schema): name = fields.Str() age = fields.Integer() @post_load def make(self, data, **kwargs): return User(**data) schema = UserSchema() users = schema.load(data, many=True)
如果是单个数据，只需要把load方法的many参数去掉。
验证功能
示例1:
from marshmallow import ValidationError try: schema = UserSchema() user, error = schema.load(data) print(user, error) except ValidationError as e: print(‘e.message‘, e.messages) print(‘e.valid_data‘, e.valid_data)
e.message和e.valid_data包括了错误的信息和正确的字段结果，结果如下：
示例2（更多的验证内容）:
from pprint import pprint from marshmallow import fields, post_load, Schema, validate, ValidationError class UserSchema(Schema): name = fields.Str(validate=validate.Length(min=3)) permission = fields.Str(validate=validate.OneOf([‘read‘, ‘write‘, ‘admin‘])) age = fields.Integer(validate=validate.Range(min=18, max=70)) data = {"name": "fa", "permission": ‘user‘, "age": 17} try: UserSchema().load(data) except ValidationError as e: pprint(e.messages)
验证的结果如下：
示例3(自定义认证信息):
from pprint import pprint from marshmallow import fields, post_load, Schema, validate, ValidationError def validate_quantity(num): if num < 0: raise ValidationError(‘必须大于0‘) if num > 20: raise ValidationError(‘必须小于20‘) class ItemSchema(Schema): quantity = fields.Integer(validate=validate_quantity) data = {‘quantity‘: 21} try: result = ItemSchema().load(data) except ValidationError as e: pprint(e.messages)
输出结果如下：
更优雅的写法：
from pprint import pprint from marshmallow import fields, post_load, Schema, validates, ValidationError class ItemSchema(Schema): quantity = fields.Integer() @validates(‘quantity‘) def validate_quantity(self, num): if num < 0: raise ValidationError(‘必须大于0‘) if num > 20: raise ValidationError(‘必须小于20‘) data = {‘quantity‘: 21} try: result = ItemSchema().load(data) except ValidationError as e: pprint(e.messages)
示例4（必填字段）:
from pprint import pprint from marshmallow import fields, post_load, Schema, validates, ValidationError class UserSchema(Schema): name = fields.String(required=True, error_messages={‘required‘: ‘必填字段‘}) age = fields.Integer(required=True, error_messages={‘required‘: ‘必填字段‘}) email = fields.Email() try: result = UserSchema().load({‘email‘: ‘foo@bar.com‘}) except ValidationError as e: pprint(e.messages)
示例5（默认字段）:
from marshmallow import Schema, fields import datetime import uuid class UserSchema(Schema): id = fields.UUID(missing=uuid.uuid1) birthdate = fields.DateTime(default=datetime.datetime(2020, 2, 25)) print(UserSchema().load({})) print(UserSchema().dump({}))
结果信息：
更多请参考官方文档：https://marshmallow.readthedocs.io/en/stable
标签：rmi time field class res 结果 参数 item png
原文地址：https://www.cnblogs.com/yangjintao/p/12360909.html
