【Python】(Essential Marshmallow) Marshmallow Nested post_load behaviour

痛定思痛。 2022-09-10 05:23 143阅读 0赞

# Essential Marshmallow - Nested post\_load behaviour #

`nested_and_load.py`:

from typing import Any
    
    from marshmallow import Schema
    from marshmallow import fields
    from marshmallow import post_load
    
    
    def evlove(val, type_):
        if type_ == 'int':
            return int(val)
        if type_ == 'float':
            return float(val)
        if type_ == 'str':
            return str(val)
    
    
    class DynamicYYDS(Schema):
        value = fields.String()
        type = fields.String()
    
        @post_load
        def evlove(self, data, **kw) -> Any:
            return evlove(data['value'], data['type'])
    
    
    class Nested(Schema):
        name = fields.String()
        value = fields.Nested(DynamicYYDS)
    
        @post_load
        def mapping(self, data, **kw):
            # marshmallow.exceptions.ValidationError: {'_schema': ['Invalid input type.']}
            # return {data['name']:  DynamicYYDS().load(data['value'])}
            return {
        data['name']: data['value']}
    
    
    if __name__ == '__main__':
        # First Level
        print(123 == DynamicYYDS().load({
        'value': '123', 'type': "int"}))
        print('abc' == DynamicYYDS().load({
        'value': 'abc', 'type': "str"}))
        print(3.1415 == DynamicYYDS().load({
        'value': '3.1415', 'type': "float"}))
    
        # Nested
        print({
        'foo': 123} == Nested().load({
        "name": "foo",
                                             "value": {
        "value": "123",
                                                       "type": "int"}}))
        print({
        'bar': 'abc'} == Nested().load({
        'name': 'bar',
                                               'value': {
        'value': 'abc',
                                                         'type': 'str'}}))
        print( {
        'spam': 3.1415} == Nested().load({
        'name': 'spam',
                                                  'value': {
        'value': '3.1415',
                                                            'type': 'float'}}))

$ python nested_and_load.py
    True
    True
    True
    True
    True
    True