Page not found for Multipage app when running the code as a module

Dash Python
1

Dash version 2.2.0 and dash-labs is installed

I am creating a multipage app with the latest dash version and trying to execute the scripts as python package. I get an error of page not found even when the pages folder exists with the relevant .py files. However, when I run the file (app.py) as a script (from Pycharm’s Run button option in the IDE), the app works fine.

I am using the example from Adams github repo: Dash-by-Plotly/Dash_More_Advanced_Shit/Multipage_app at master · Coding-with-Adam/Dash-by-Plotly · GitHub

The folder hierarchy is:

├───folder1
│   ├───folder2
│   │   └───pages
│   │       app.py

And I run the script as python -m folder1.folder2.app

Is there anything extra step to run the script as a module?

Note: I was already using dash all this time and running it as a module which worked fine. Now, I want to upgrade the app to multipage app.

Thanks!

2

Did you try moving into “folder2” and running the app from there?

3

Yes, moving into folder2 and then executing the code as a module works!

However, in my original project, I need to run my code from the root directory (which is equivalent to folder1 having several sub-folders). There would be problem in calling other modules if I move to the folder containing app.py for execution.

Any solution regarding how can I execute the script from folder1?

4

I think that your issue can be considered as a bug in the pages plugin. What do you say, @AnnMarieW ? :slight_smile:

1 Like
5

I believe you can work around the issue by adding the following snippet at the top of app.py,

import os
os.chdir(os.path.dirname(os.path.abspath(__file__)))
6

I get ModuleNotFoundError as follows:

File “D:\ …\lib\site-packages\dash_labs\plugins\pages.py”, line 292, in _import_layouts_from_pages
page_module = importlib.import_module(f"pages.{page_filename}")

image

At the same time, I would like to point out that in Pycharm, I register_page and page_registry are not found as shown below from the editor snip. Note that still the program runs successfully (of course executed as a script or as a module from the same path). Any information on this?

image

image

7

Hi @hundredmiles and @Emil

Yes, this is a bug in the pages plugin. I fixed it in the pull request to add\pages to dash, but it looks like it may be a while until that PR is reviewed. I’ll do a PR to fix it in dash-labs as well.

1 Like
8

Thanks @AnnMarieW for the information. Will wait for the fix. Also, thanks @Emil for your insights.

9

@AnnMarieW This bug you mentioned 2 posts up (in 2022) is solved I guess?
I am running into some issues with pages not being found, but the likelihood is high that I made a coding mistake. I am looking for clues in the forum right now.

10

Hi @plotplot and welcome to the Dash community :slight_smile:

Yes, this issue has been solved. As you noted, this thread is quite old.

Can you make a minimal example that replicates the issue? You can find lots of examples here:

11

Thank you very much @AnnMarieW .
I started new thread with example here: