[Python] Pydantic - parse a list of objects from YAML configuration file

I want to read a list of objects from a YAML file:

- entry1:
attribute: "Test1"
amount: 1
price: 123.45
- entry2:
attribute: "Test1"
amount: 10
price: 56.78


For this data structure i created three nested models as follows:

# Models
class EntryValues(BaseModel):
attribute: str
amount: int
price: float

class Entry(BaseModel):
entry1: EntryValues
entry2: EntryValues
class Config(BaseModel):
__root__: list[Entry]



My code to read the YAML config file looks as follows:

# get YAML config path
def get_cfg_path() -> Path:
return CWD

# read YAML file
def read_cfg(file_name: str, file_path: Path = None) -> YAML:
if not file_path:
file_path = get_cfg_path()

if file_path:
try:
file = open(file_path / file_name, "r")
except Exception as e:
print(f"open file {file_name} failed", e)
sys.exit(1)
else:
return load(file.read())
else:
raise Exception(f"Config file {file_name} not found!")


Now i want to unpack the values of the YAML to my model. For that i tried to unpack the values with the ** operator. I think im missing one more loop here though, but i can not get it work.

# Unpack and create config file
def create_cfg(file_name: str = None) -> Config:
config_file = read_cfg(file_name=file_name)
_config = Config(**config_file.data)
return _config


I would appreciate any help.

Update


So i played around with my model-structure a bit without using the YAML file. I dont quite get why the following throws an ValidationError:

Consider the following list of entries (thats the same data structure i would receive from my YAML file):

entries = [
{'entry1': {'attribute': 'Test1', 'amount': 1, 'price': 123.45}},
{'entry2': {'attribute': 'Test2', 'amount': 10, 'price': 56.78}}
]


If i run the following simple loop, then Pydantic throws an ValidationError:

for entry in entries:
Entry(**entry)


Error:

ValidationError: 1 validation error for Entry
entry2
field required (type=value_error.missing)


However, if the list only contains one entry dictionary, then it works:

class Entry(BaseModel):
entry1: EntryValues
#entry2: EntryValues

entries = [
{'entry1': {'attribute': 'Test1', 'amount': 1, 'price': 123.45}}
]

for entry in entries:
Entry(**entry)


Can someone explain this or what im doing wrong here?

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