[BUG] Boolean values within pydantic base model being casted to scalar value

[jiwidi]

Describe the bug

Describe the bug

Trying to pass a pydantic model between task but its converting bool variables to int. Is there a way to make flyte work with pydantic models?

Expected behavior

For bool types to stay as bool types

Additional context to reproduce

I have this main.py file containing my workflow:

from flytekit import task, workflow
from pydantic import BaseModel

class Config(BaseModel):
    bool_var: bool

@task
def create_config() -> Config:
    return Config(bool_var=True)

@task
def check_bool(x: bool) -> bool:
    return x

@workflow
def workflow() -> bool:
    config = create_config()
    return check_bool(x=config['bool_var'])

When I run this with the command

pyflyte run issue.py workflow

I get the error:

TypeTransformerFailedError: Failed to convert inputs of task 'issue.check_bool':
  Error converting input 'x' at position 0:
  Cannot convert literal <FlyteLiteral(Literal) scalar { blob { metadata { type { format: "PythonPickle" } } uri:
"/var/folders/zr/72m6cw8x66b4g3q_s8dmy5c00000gn/T/flyte-bgc4g0zt/raw/d8a7be6139519884010995bc2aa7ddd9/cd165a40ea1442ca1acb6fbd4b3700f4" } }> to <class 'bool'>

The bool property in the Config object is converted to a scalar.

Screenshots

No response

Are you sure this issue hasn't been raised already?

• Yes

Have you read the Code of Conduct?

• Yes

[runllm]

Flyte currently has issues with handling Pydantic models, particularly with type conversions. Boolean values within Pydantic models may be cast to scalar values due to serialization issues. This is a known problem and has been discussed in the community.

Would you like more detail on potential workarounds or ongoing efforts to address this issue?

Sources:

• GitHub Issue #2686
• Flyte Discussion on Pydantic Models
• Flyte Discussion on Type Handling

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[novahow]

Hi, @jiwidi

I guess this might relate to how flyte handles complex data types. Currently as a workaround, you can try the following:

from flytekit import task, workflow
from pydantic import BaseModel

class Config(BaseModel):
    bool_var: bool


@task
def create_config() -> Config:
    return Config(bool_var=True)

@task
def check_bool(x: bool) -> bool:
    return x

@task
def bool_parser(x: Config) -> bool:
    return x.bool_var


@workflow
def wf() -> bool:
    config = create_config()
    return check_bool(x=bool_parser(x=config))

[kumare3]

fixed by - #5318