How to run and deploy a simple Python code using Azure Functions from VS Code?

@Krishna Chowdary Paricharla Thank you so much again!

I tried deploying by first go to "Explorer" in (VS Code), and did F1 --> Azure Functions: Deploy to Azure --> (selected subscription) --> (selected function app) ,but nothing got deployed.

When I looked at the details, it says "No HTTP triggers found."

Then, I try again by going to "Azure" in (VS Code), and did F1, and did the same procedure, but, nothing got deployed again.

When I looked at the details, it says "No HTTP triggers found."

I am not sure at which point, "http_trigger" gets created.

Hello Justin Doh,

The reason you’re seeing “No HTTP triggers found” is that your current project does not define any HTTP-triggered functions that the Azure Functions runtime can detect.

When does the http_trigger get created?

• The http_trigger function isn’t created automatically on deploy.
• It is generated only when you create a new Function (with HTTP trigger template) locally using VS Code.
• For Python (isolated model), this adds code in function_app.py with something like:

    import azure.functions as func
    app = func.FunctionApp()
    @app.function_name(name="HttpExample")
    @app.route(route="http_example")
    def main(req: func.HttpRequest) -> func.HttpResponse:
    return func.HttpResponse("Hello from Azure Function!")
    
  

Without this, the runtime has no route to expose → hence the message “No HTTP triggers found

Why your current deployment shows nothing

Looking at your folder in VS Code (function_app.py, convert.py, etc.), it seems:

• function_app.py may not actually contain a valid trigger decorated with @app.route().
• convert.py is your business logic, but Azure won’t pick it up unless it’s called from a trigger function in function_app.py.

How to fix it

• In VS Code, create a new function inside your Function App project:
• F1 → Azure Functions: Create Function → HTTP Trigger → Python → provide a name.
• This will add the correct trigger definition in function_app.py.
• Then, modify that function to call your code in convert.py. For example:

import azure.functions as func
from convert import process_csv   # your own script
app = func.FunctionApp()
@app.function_name(name="RunCsvFunction")
@app.route(route="run-csv")
def main(req: func.HttpRequest) -> func.HttpResponse:
    result = process_csv()
    return func.HttpResponse(f"Done: {result}")

Deployment process reminder

• Always deploy from the project root (the folder that contains function_app.py, host.json, requirements.txt).
• VS Code pushes the entire folder. If the trigger exists locally and runs with func start, it will show up in Azure after deploying.

The http_trigger only exists if you create it in your code (@app.route). Right now, Azure doesn’t see any HTTP function in function_app.py, so deployment shows “No HTTP triggers found.” Add (or re-create) an HTTP trigger locally, then deploy again — your Logic App will then be able to call it.

@Krishna Chowdary Paricharla

Do I need other Python code besides bottom code inside "function_app.py" in order to create "http_trigger"?

import azure.functions as func
from convert import process_csv   # import your logic

app = func.FunctionApp()

@app.function_name(name="RunCsvFunction")
@app.route(route="run-csv")
def main(req: func.HttpRequest) -> func.HttpResponse:
    result = process_csv()
    return func.HttpResponse(f"Done: {result}")

Justin Doh,

No extra Python code is needed. The snippet you posted is already a valid HTTP trigger. Just make sure your project has the correct folder structure and required files (host.json, requirements.txt) so the runtime can recognize it.

@Krishna Chowdary Paricharla

Thank you!

So, I tried different things.

I created a new Function App, and this one appears to be more stable ("HTTP_Trigger" gets created in Azure Function App when I use the original Python code) than previous Function App that I was using for last few days.

I was able to go to step by "Create new project" each time, and this process seem to make it work to at least to publish all files.

But "HTTP_Trigger" that I had earlier got disappeared (when I refreshed it).

It disappeared when I tried with the new Python code.

Do you think there is something missing from the Python code at "function_app.py"?

This is error message after I refreshed it and disappeared:

Bottom is my code. Thank you!

import azure.functions as func
from convert import process_csv   # import your logic

app = func.FunctionApp()

@app.function_name(name="http_trigger")
@app.route(route="run-csv")
def main(req: func.HttpRequest) -> func.HttpResponse:
    result = process_csv()
    return func.HttpResponse(f"Done: {result}")

Hello Justin Doh,

Your function_app.py code is already correct — nothing is missing for the HTTP trigger.

The reason the function disappears after refresh is not the code, but usually one of these:

convert.py not deployed (make sure it’s in the same project folder as function_app.py).

Missing dependencies (add any libraries used in convert.py to requirements.txt).

Deployed from the wrong folder (you must deploy the folder that contains function_app.py, host.json, and requirements.txt).

Run func start locally — if you don’t see the HTTP trigger locally, Azure also won’t load it.

When you redeploy from VS Code, Azure Functions always pushes the entire local project folder, not individual files. That means if a function (like your old http_trigger) isn’t present in your local codebase at deployment time, it won’t exist in Azure afterward.

To make sure everything works as expected:

Keep both your trigger (function_app.py) and your logic file (e.g., my_script.py) inside the same project folder.

Import your script from function_app.py so Azure Functions runtime can call it.

Use the folder structure like this:

MyFunctionApp/
├── function_app.py
├── my_script.py
├── requirements.txt
├── host.json
└── local.settings.json

When you modify your code, just redeploy the full project folder using: F1 → Azure Functions: Deploy to Function App → select subscription → select your Function App.

This way your custom Python script will be deployed alongside the trigger definition.

As a side tip — when handling CSV data or verifying output, I sometimes double-check results with quick tools like this scientific calculator. It’s handy for quick math or calculation checks while debugging Python functions. In fact, tools like that can be really useful when you need to validate transformations on numbers in your CSVs or just confirm that your logic is producing the expected outputs. I’ve found it saves time compared to writing extra debug code just to verify.

@Krishna Chowdary Paricharla Thank you.

I am trying to make sure I have necessary lines inside "requirelments.txt".

Currently my logic file "convert.py" has following codes on the top (where "import(s)" are):

from azure.storage.fileshare import ShareServiceClient 
import pandas as pd
import io

Do I have to indicate as below inside "requirements.txt"?

Also, I am not sure what you meant by "Run func start locally — if you don’t see the HTTP trigger locally, Azure also won’t load it."

BTW, when I run the code "function_app.py" from my local machine, it works (result get done as expected).

Thanks.

@Keisanki Dentaku Thank you for your feedback.

I have replied to Krishna's comment on the top.

I will wait for her response, but I have a question for you.

When you mentioned ".. if a function (like your old http_trigger) isn’t present in your local codebase at deployment time" , currently, I am using code below and deploy (replacing the original "http_trigger" code that was provided:

import azure.functions as func
from convert import process_csv   # import your logic

app = func.FunctionApp()

@app.function_name(name="http_trigger")
@app.route(route="run-csv")
def main(req: func.HttpRequest) -> func.HttpResponse:
    result = process_csv()
    return func.HttpResponse(f"Done: {result}")

It should work, correct?
Thanks.

Hello Justin Doh,

Could you please try zip deployment is a method.

Because With zip deployment, the structure of your app, including all files like function_app.py, convert.py, and any required dependencies (like requirements.txt), is bundled together in a single .zip file. This can prevent issues where the Azure Functions app can't locate your files correctly after deploying them in a non-zipped form.

By using zip deployment, you should eliminate any potential issues related to the missing files, and ensure your function app is loaded correctly.

Let me know if you need further assistance!

Hello Justin Doh,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.

@Praveen Kumar Gudipudi Thank you for your suggestions. I thought zip method only applies to Azure Logic App. Do you have any reference URL for this by chance? I am just not understanding how zip method would work in Azure Function. Thanks.

Hello Justin Doh,

• ZIP deployment is valid and supported for Azure Functions.
• It helps ensure that all files and dependencies are deployed correctly.

Zip deployment for Azure Functions

https://github.com/MicrosoftDocs/azure-docs/blob/main/articles/azure-functions/deployment-zip-push.md

Please check above documents and let me know with an update.

Hello Justin Doh,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.