topic Re: call function in user data functions in Data Engineering

call function in user data functions

bruinsmm — Tue, 25 Nov 2025 12:34:53 GMT

i have the following code in user data functions:

@udf.connection(argName="varLib", alias="varlib")

@udf.function()

async def get_environment(varLib: fn.FabricVariablesClient) -> str:

variables = varLib.getVariables()

omgeving = variables["omgeving"]

return omgeving

@udf.function()

async def get_result() -> str:

result = get_environment()

return result

when i call the function get_environment function via function get_result , i got the following message:
<coroutine object get_environment at 0x78c6d405c880>

how can i get the the right one result.

Re: call function in user data functions

OnurOz — Tue, 25 Nov 2025 14:30:06 GMT

Hi @bruinsmm

(Edited my reply to fix the code, due the error mentioned here)

To get the correct value, modify get_result so it awaits get_environment. In Python with async/await, this means:

@udf.connection(argName="varLib", alias="varlib") @udf.function() async def get_environment(varLib: fn.FabricVariablesClient) -> str: variables = varLib.getVariables() omgeving = variables["omgeving"] return omgeving @udf.function() async def get_result() -> str: result = await get_environment(varLib) # <--- FIX return result

Hope that helps

Onur

😊If this post helped you, feel free to give it some Kudos! 👍

✅And if it answered your question, please mark it as the accepted solution.

Re: call function in user data functions

bruinsmm — Tue, 25 Nov 2025 13:46:37 GMT

Hi @OnurOz

I've try your solution, but it don't work, i got the error message:

AttributeError: 'NoneType' object has no attribute 'headers'

I think the problem is in the call function without VarLib parameter: get_environment()

@udf.connection(argName="varLib", alias="varlib")

@udf.function()

async def get_environment(varLib: fn.FabricVariablesClient) -> str:

variables = varLib.getVariables()

omgeving = variables["omgeving"]

return omgeving

@udf.function()

async def get_result() -> str:

result = await get_environment() # <-- await it

return result

Re: call function in user data functions

tayloramy — Tue, 25 Nov 2025 14:16:55 GMT

Hi @bruinsmm,

Yes, you will need to pass in a valid varLib object as a parameter to the get_environment call.

If you found this helpful, consider giving some Kudos. If I answered your question or solved your problem, mark this post as the solution.

Re: call function in user data functions

OnurOz — Tue, 25 Nov 2025 14:20:55 GMT

sorry my bad, I've forgotten to add varlib to the call get_environment(), following code should do the work:

@udf.function() @udf.connection(argName="varLib", alias="varlib") async def get_environment(varLib: fn.FabricVariablesClient) -> str: variables = varLib.getVariables() return variables["omgeving"] @udf.function() @udf.connection(argName="varLib", alias="varlib") async def get_result(varLib: fn.FabricVariablesClient) -> str: result = await get_environment(varLib) # I've forgotten this return result

Re: call function in user data functions

bruinsmm — Tue, 25 Nov 2025 14:43:07 GMT

I have try the code. It don't work :☹️

got the same error message: "error_message": "'NoneType' object has no attribute 'headers'"

@udf.connection(argName="varLib", alias="varlib")

@udf.function()

async def get_environment(varLib: fn.FabricVariablesClient) -> str:

variables = varLib.getVariables()

return variables["omgeving"]

@udf.connection(argName="varLib", alias="varlib")

@udf.function()

async def get_result(varLib: fn.FabricVariablesClient) -> str:

result = await get_environment(varLib) # I've forgotten this

return result

Re: call function in user data functions

OnurOz — Tue, 25 Nov 2025 20:51:42 GMT

use this code (tested & working):

import datetime import fabric.functions as fn import logging udf = fn.UserDataFunctions() async def get_environment_local(varLib: fn.FabricVariablesClient) -> str: variables = varLib.getVariables() # sync call return variables["omgeving"] async def get_result_local(varLib: fn.FabricVariablesClient) -> str: return await get_environment_local(varLib) @udf.connection(argName="varLib", alias="varlib") @udf.function() async def hello_fabric(name: str, varLib: fn.FabricVariablesClient) -> str: logging.info("Running hello_fabric") omgeving = await get_result_local(varLib) return ( f"Welcome to Fabric Functions, {name}. " f"Omgeving: {omgeving}. " f"Time: {datetime.datetime.now()}" )

When a function has @udf.function(), it becomes a remote Fabric function, not a normal Python function. Calling it directly (await get_environment(varLib)) bypasses Fabric's runtime, so the injected connection becomes None, and Fabric later tries to access None.headers, causing the NoneType error. Make helper functions local (not decorated) so they behave like real Python functions.

Therefore I modified the code to remove the @udf.function() decorators from the helper functions and turn them into normal local Python functions, so they no longer get wrapped by the Fabric runtime and can be safely called from inside the main UDF with a valid varLib connection.

Re: call function in user data functions

bruinsmm — Wed, 26 Nov 2025 12:40:42 GMT

@OnurOz I have tried your code. It works!!. Thanks for your help and explanation about decorators.