如何实现无需重复传入类本身即可获取Pydantic类的所有字段名？

Absolutely, there are several straightforward ways to clean up your implementation so you don't have to pass the class itself to get_all_fields(), or even make the field list directly accessible as a class property. Let's walk through the best options:

Option 1: Use a @classmethod for Dynamic Field Retrieval #

The simplest fix is to convert your get_all_fields method into a class method. This way, the method automatically receives the class itself as its first parameter (cls), eliminating the need to pass it manually.

Here's the updated code:

from pydantic import BaseModel

class AdaptedModel(BaseModel):
    @classmethod
    def get_all_fields(cls, alias=False):
        return list(cls.schema(by_alias=alias).get("properties").keys())

class TestClass(AdaptedModel):
    test: str

Now you can call it cleanly like this:

# No need to pass TestClass twice!
fields = TestClass.get_all_fields()
# With alias=True if you need to use field aliases
fields_with_aliases = TestClass.get_all_fields(alias=True)

This keeps the flexibility of toggling the alias parameter while making the call syntax intuitive and readable.

Option 2: Auto-Generate a Class Property for Static Field Access #

If you don't need to dynamically switch the alias parameter and just want direct, one-shot access to the field list, you can use __init_subclass__ to compute the fields once when the subclass is defined. This is more efficient since it runs only once, not every time you request the fields.

Updated code:

from pydantic import BaseModel

class AdaptedModel(BaseModel):
    def __init_subclass__(cls, **kwargs):
        super().__init_subclass__(**kwargs)
        # Store regular field names as a class attribute
        cls.all_fields = list(cls.schema().get("properties").keys())
        # Optional: Add alias-based fields if you need them
        cls.all_fields_with_aliases = list(cls.schema(by_alias=True).get("properties").keys())

class TestClass(AdaptedModel):
    test: str

Now you can access the fields directly without any method calls:

print(TestClass.all_fields)  # Output: ['test']
# If you added the alias version:
# print(TestClass.all_fields_with_aliases)

Which Option Should You Choose? #

• Use the @classmethod approach if you need the flexibility to sometimes retrieve fields using their aliases (via the alias parameter).
• Use the class property approach if you just need a static list of field names and want the most concise, readable access possible.

Both solutions eliminate the clunky dm.TestClass.get_all_fields(dm.TestClass) syntax and make your code much cleaner.

内容的提问来源于stack exchange，提问作者5th