我有这些序列化器：

class OneSerializer(serializers.ModelSerializer):
    class Meta:
        model = OneModel
        fields = ['time_column', 'event_column']

class TwoSerializer(serializers.ModelSerializer):
    survival_columns = OneSerializer(many=True, required=False)
    
    class Meta:
        model = UserFile
        fields = ['id', 'name', 'survival_columns']

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现在，在create方法中，我试图从validated_data中检索survival_columns值，但**它不存在！**如果我打印POST数据，字段和值将正确显示：

def create(self, validated_data):
   print(self.context['request'].POST)  # <QueryDict: {'name': ['Clinical data.csv'], 'survival_columns': ['{"event_column":"Test","time_column":"Test"}']}>
   print(validated_data)  #  {'name': 'Clinical data.csv'}

型
为什么要从请求中过滤字段survival_columns？