如何在使用PyYAML序列化对象时忽略成员？

Question

序列化此对象时，如何忽略成员Trivial._ignore？

import yaml 
class Trivial(yaml.YAMLObject): 
    yaml_tag = u'!Trivial' 
    def __init__(self): 
     self.a = 1 
     self.b = 2 
     self._ignore = 3 

t = Trivial() 
print(yaml.dump(t)) 

打印

!Trivial 
_ignore: 3 
a: 1 
b: 2 

Answer 1

def my_yaml_dump(yaml_obj): 
    my_ob = deepcopy(yaml_obj) 
    for item in dir(my_ob): 
     if item.startswith("_") and not item.startswith("__"): 
      del my_ob.__dict__[item] 
    return yaml.dump(my_ob) 

这样的事情会忽略与单个（领先）任何下划线

我想这是你想要的

class Trivial(yaml.YAMLObject): 
    yaml_tag = u'!Trivial' 
    def __init__(self): 
     self.a = 1 
     self.b = 2 
     self._ignore = 3 
    @classmethod 
    def to_yaml(cls, dumper, data): 
     # ... 
     my_ob = deepcopy(data) 
     for item in dir(my_ob): 
      if item.startswith("_") and not item.startswith("__"): 
       del my_ob.__dict__[item] 
     return dumper.represent_yaml_object(cls.yaml_tag, my_ob, cls, 
               flow_style=cls.yaml_flow_style) 

虽然一个更好的会面明确HOD（文体）

class SecretYamlObject(yaml.YAMLObject): 
    hidden_fields = [] 
    @classmethod 
    def to_yaml(cls,dumper,data): 
     new_data = deepcopy(data) 
     for item in cls.hidden_fields: 
      del new_data.__dict__[item] 
     return dumper.represent_yaml_object(cls.yaml_tag, new_data, cls, 
              flow_style=cls.yaml_flow_style) 

class Trivial(SecretYamlObject): 
    hidden_fields = ["_ignore"] 
    yaml_tag = u'!Trivial' 
    def __init__(self): 
     self.a = 1 
     self.b = 2 
     self._ignore = 3 

print yaml.dump(Trivial()) 

这是秉承蟒蛇的口头禅是比隐