我正在尝试使用Python将protobuf文件转换为Objective-C类。例如,给定protobuf消息:
message Person {
required string name = 1;
required int32 id = 2;
optional string email = 3;
}
我想将其转换为objc类:
@interface Person : NSObject
@property (nonatomic, copy) NSString *name;
@property (nonatomic, assign) int ID;
@property (nonatomic, copy) NSString *email;
@end
关键是获取每个属性的名称和类型。例如,protobuf消息中的“可选字符串电子邮件”,其名称为“ email”,类型为“ string”,因此在Objective-c中应为NSString * email。我遵循了官方教程,编写了一个与本教程相同的addressbook.proto并对其进行了编译。然后我写了我的python代码:
import addressbook_pb2 as addressbook
p = addressbook.Person()
all_fields = p.DESCRIPTOR.fields_by_name
# print "all fields: %s" %all_fields
field_keys = all_fields.keys()
# print "all keys: %s" %field_keys
for key in field_keys:
one_field = all_fields[key]
print one_field.label
这给了我:
1
2
3
2
所以我想标签不是我所需要的,而field_keys只是我期望的名称列表。我尝试了其他一些单词,并在网络上进行了一些搜索,但没有找到正确的答案。
如果没有获取类型的方法,我还有另外一种想法,那就是以纯Pythonic的方式读取和分析protobuf源文件的每一行,但是我真的不想这样做,必要。
有人可以帮我吗?
感谢马克的回答,我想出了一些解决方案。这只是一个想法,但这对我来说是巨大的一步。
Python代码:
import addressbook_pb2 as addressbook
typeDict = {"1":"CGFloat", "2":"CGFloat", "3":"NSInteger", "4":"NSUinteger", "5":"NSInteger", "8":"BOOL", "9":"NSString", "13":"NSUinteger", "17":"NSInteger", "18":"NSInteger"}
attrDict = {"CGFloat":"assign", "NSInteger":"assign", "NSUinteger":"assign", "BOOL":"assign", "NSString":"copy"}
p = addressbook.Person()
all_fields = p.DESCRIPTOR.fields_by_name
field_keys = all_fields.keys()
for key in field_keys:
one_field = all_fields[key]
typeNumStr = str(one_field.type)
className = typeDict.get(typeNumStr, "NSObject")
attrStr = attrDict.get(className, "retain")
propertyStr = "@property (nonatomic, %s) %s *%s" %(attrStr, className, key)
print propertyStr
对于地址簿示例,它打印:
@property (nonatomic, copy) NSString *email
@property (nonatomic, copy) NSString *name
@property (nonatomic, retain) NSObject *phone
@property (nonatomic, assign) NSInteger *id
不是最终的解决方案,但这意味着很多。谢谢马克!
FieldDescriptor类具有一个message_type
成员,如果是复合字段,则为该字段中包含的消息类型的描述符。否则,为无。
通过在DESCRIPTORS
的字典中进行迭代来组合在一起意味着您可以获得复合和非复合(原始)字段的name和type。
import addressbook_pb2 as addressbook
DESCRIPTORS = addressbook.Person.DESCRIPTOR.fields_by_name
for (field_name, field_descriptor) in DESCRIPTORS.items():
if field_descriptor.message_type:
# Composite field
print(field_name, field_descriptor.message_type.name)
else:
# Raw type
print(field_name, field_descriptor.type)
# TYPE_DOUBLE
# TYPE_FLOAT
# TYPE_INT64
# TYPE_UINT64
# TYPE_INT32
# TYPE_FIXED64
# TYPE_FIXED32
# TYPE_BOOL
# TYPE_STRING
# TYPE_GROUP
# TYPE_MESSAGE
# TYPE_BYTES
# TYPE_UINT32
# TYPE_ENUM
# TYPE_SFIXED32
# TYPE_SFIXED64
# TYPE_SINT32
# TYPE_SINT64
# MAX_TYPE
原始类型是类属性; https://github.com/protocolbuffers/protobuf/blob/master/python/google/protobuf/descriptor.py