# how to create a global variable in python function
**URL:** https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822
**Category:** General
**Tags:** function-node
**Created:** [23 January 2024 07:52 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822 "2024-01-23T07:52:58Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Kleisi](https://discourse.nodered.org/u/Kleisi)
#### Post date: [23 January 2024 07:52 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/1 "2024-01-23T07:52:59Z")
Hello
Can someone tell me how to create a global variable in a Python function
node-red-contrib-python-function
Node Red V3.1.3
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [23 January 2024 07:58 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/2 "2024-01-23T07:58:45Z")
Hello @Kleisi, welcome to the forum.
Can you explain why you want to do that?
Would it work to set the variable in a change node using the output of your python node?
---
### Author:  [@Kleisi](https://discourse.nodered.org/u/Kleisi)
#### Post date: [23 January 2024 08:13 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/3 "2024-01-23T08:13:31Z")
Hello
I want to count signals or use calculations in other Python functions in other flows
and because I'm just interested 🙂
---
### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [23 January 2024 08:46 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/4 "2024-01-23T08:46:09Z")
I could be wrong,
But what you are trying to achieve is not possible.
Each python function node creates a new python process.
You don’t have the likes of global variables with this approach.
Like @jbudd says - use the Node RED globals to pass values to and from the python scripts.
But remember - the scripts are not in the same process as they are in Node RED
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [23 January 2024 10:11 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/5 "2024-01-23T10:11:24Z")
Or replace the python functions with node red flows.
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [23 January 2024 12:27 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/6 "2024-01-23T12:27:58Z")
> [@Kleisi](#):
>
> I want to ... use calculations in other Python functions in other flows
There is a valuable and little known feature in Node-red for passing data between different flow tabs and internal & external processes: messages.
You can think of a message like a railway train. It travels along a prescribed track. At every stop different people and luggage can join the train and they are carried safely onward to their destination.
> [@Kleisi](#):
>
> I want to count signals
A context variable is a viable way to do this. But global context is ridiculous overkill. Use a variable whose scope is restricted to a flow or even a single node and _put that value on the train_ for use further down the track.
A little javascript function to achieve this:
```auto
let signalCount = context.get("signalCount") || 0
signalCount += 1
context.set("signalCount", signalCount)
msg.signalCount = signalCount
return msg
```
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [23 March 2024 12:28 UTC](https://discourse.nodered.org/t/how-to-create-a-global-variable-in-python-function/84822/7 "2024-03-23T12:28:08Z")
This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.