Local variable referenced before assignment

Anvil Q&A
1

My app is connected to a Pico W, and I’m trying to use the following code to send the “ftx_dspsave1” command. I have several other similar server calls in my code that work as intended, but this one seems to cause the “Error: local variable referenced before assignment”

This seems very similar to a bug discussed here: [Fixed] UnboundLocalError: local variable 'anvil' referenced before assignment

from anvil import *
import anvil.facebook.auth
import anvil.server
import anvil.google.auth, anvil.google.drive
from anvil.google.drive import app_files
import anvil.users
import anvil.tables as tables
import anvil.tables.query as q
from anvil.tables import app_tables

class Dose(DoseTemplate):
  def __init__(self, **properties):
    # Set Form properties and Data Bindings.
    self.init_components(**properties)
    #TODO: put items in designer

  def button_1_click(self, **event_args):
    """This method is called when the button is clicked"""
    anvil.server.call_s("ftx_dspsave1")
    pass

Thanks in advance

2

Welcome to the Forum!

I see nothing in this code that creates or references any local variables.

Do you have any Data Bindings in your visual components? The references might be occurring there.

3

Thanks for the reply. You can tell why I’m confused- there are no variables I’m trying to reference. I can replace anvil.server.call_s(“ftx_dspsave1”) with several other calls that work just fine, but for some reason this call (and anvil.server.call_s(“ftx_dspsave2”) cause the variable reference error.

I have no data bindings anywhere in my app. I’m still learning Anvil and haven’t found a use for data bindings yet… mainly because I don’t know how they work.

4

Can you provide more details about the error?
At what line does it happen?
Can you show the traceback?

5

Yes, sorry, I should have included that the first time. Knew I forgot something…

Error: local variable referenced before assignment
at Setup, line 26

Line 26:

    anvil.server.call_s("ftx_dspsave1")
6

Can you show the full traceback? Seeing what call what may help.

Have you tried changing the name of ftx_dspsave2, both the function definition and where it is called?

Or moving it to another module?

Or commenting out all its code and immediately returning?

7

Thanks for the ideas - I haven’t solved the problem but I am now confident it’s not in the code on Anvil.

I commented out everything run by the command on the Pico and the command worked without error. I’ll have to dig into that code to find the culprit. I was thrown off by the error traceback only appearing on the Anvil side.

Thanks again for the help!