Attempt to split up pydantic calls amongst multiple processes

pydantic-error.py

#!/usr/bin/python3

import asyncio
import pickle
from concurrent.futures import ProcessPoolExecutor, ThreadPoolExecutor

import pydantic as p


class Model(p.BaseModel):
    class Config:
        extra = p.Extra.forbid
    digit: p.constr(regex='^[0-9]*$')

def normalize(data):
    out = Model(digit=data)    
    print(data)
    return out 
    
def workaround(data):
    try:
        out = Model(digit=data)
    except Exception as e:
        raise ValueError('pydantic Validation error: %s' % str(e))
    print(data)
    return out 
                                                                   
async def main():
    normalizers = []
    loop = asyncio.get_running_loop()
    executor = ProcessPoolExecutor(max_workers=1)
    for i in ('a', '1', '2'):
        normalizers.append(loop.run_in_executor(executor, normalize, i))
        
    return await asyncio.gather(*normalizers, return_exceptions=True)
                                                                        
models = asyncio.run(main())

print(models)

traceback

# Output when using normalize()
1
2
[BrokenProcessPool('A process in the process pool was terminated abruptly while the future was running or pending.'), 
BrokenProcessPool('A process in the process pool was terminated abruptly while the future was running or pending.'), 
BrokenProcessPool('A process in the process pool was terminated abruptly while the future was running or pending.')]



# Output from workaround()
1
2
[ValueError('pydantic Validation error: 1 validation error for Model\ndigit\n  string does not match regex "^[0-9]*$" (type=value_error.str.regex; pattern=^[0-9]*$)'),
Model(digit='1'), Model(digit='2')]