ModuleNotFoundError: No module named 'pages.' #113

charmeem · 2022-06-13T05:59:57Z

When trying to run the demo code of Chapter08-MultiPageDashApp I am getting this error.
This error however doesn't generates if I include only histogram.py file in /pages folder.
As I add other files like bar_charts.py this error appears.

Detail print out:

(base) c:\my_drive\python\dashboards\plotlydash\flaskdash1>python app.py
Traceback (most recent call last):
  File "app.py", line 6, in <module>
    app = dash.Dash(
  File "C:\Users\hp\anaconda3\lib\site-packages\dash\dash.py", line 420, in __init__
    plugin.plug(self)
  File "C:\Users\hp\anaconda3\lib\site-packages\dash_labs\plugins\pages.py", line 327, in plug
    _import_layouts_from_pages(pages_folder)
  File "C:\Users\hp\anaconda3\lib\site-packages\dash_labs\plugins\pages.py", line 301, in _import_layouts_from_pages
    page_module = importlib.import_module(f"pages.{page_filename}")
  File "C:\Users\hp\anaconda3\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 973, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'pages.'

The text was updated successfully, but these errors were encountered:

charmeem · 2022-06-13T06:43:04Z

This issue is resolved after upgrading dash to 2.5 and following suggestions in earlier issue#112

charmeem · 2022-06-13T07:09:51Z

However Now I am getting ' Duplicate callback Outputs' for every callback although there is no duplicate Output exits.

Error:

In the callback for output(s):
  histograms-graph.figure
Output 0 (histograms-graph.figure) is already in use.
Any given output can only have one callback that sets it.
To resolve this situation, try combining these into
one callback function, distinguishing the trigger
by using `dash.callback_context` if necessary.

histogram.py file:

from dash import Dash, dcc, html, Input, Output, callback
from dash import register_page
import plotly.express as px
import numpy as np

register_page(__name__)

np.random.seed(2020)

layout = html.Div(
    [
        dcc.Graph(id="istograms-graph"),
        html.P("Mean:"),
        dcc.Slider(
            id="histograms-mean", min=-3, max=3, value=0, marks={-3: "-3", 3: "3"}
        ),
        html.P("Standard Deviation:"),
        dcc.Slider(id="histograms-std", min=1, max=3, value=1, marks={1: "1", 3: "3"}),
    ]
)


@callback(
    Output("histograms-graph", "figure"),
    Input("histograms-mean", "value"),
    Input("histograms-std", "value"),
)
def display_color(mean, std):
    
    data = np.random.normal(mean, std, size=500)
    fig = px.histogram(data, nbins=30, range_x=[-10, 10])
    return fig

charmeem · 2022-06-13T07:12:16Z

import dash
import dash_bootstrap_components as dbc


app = dash.Dash(
    __name__, use_pages=True, external_stylesheets=[dbc.themes.BOOTSTRAP]
)

navbar = dbc.NavbarSimple(
    dbc.DropdownMenu(
        [
            dbc.DropdownMenuItem(page["name"], href=page["path"])
            for page in dash.page_registry.values()
            if page["module"] != "pages.not_found_404"
        ],
        nav=True,
        label="More Pages",
    ),
    brand="Multi Page App Plugin Demo",
    color="primary",
    dark=True,
    className="mb-2",
)

app.layout = dbc.Container(
    [navbar, dash.page_container],
    fluid=True,
)

if __name__ == "__main__":
    app.run_server(debug=True)

AnnMarieW · 2022-06-13T13:15:30Z

HI @charmeem
Are you on Windows? If so, this is a bug and will be fixed in 2.5.1. The new release with the patch is coming soon.

charmeem · 2022-06-13T18:31:54Z

Yes I am using Windows.
Will wait for the new release, thanks.

AnnMarieW · 2022-06-13T18:38:07Z

Hi @charmeem 5.1 was just released 🎊

Could you try running these multi-page sample apps and let me know how it goes?: https://github.com/AnnMarieW/dash-multi-page-app-demos

charmeem · 2022-06-13T18:51:00Z

Hello,
I have just tried after upgrading to 2.5.1 , still seeing the same errors however with one improvement.
I can see the pages in the navigation bar which was not the case before.

Secondly when I add a page 'heatmaps.py' in the /pages folder following error appears:

Exception
Exception: modules ['pages..ipynb_checkpoints.heatmaps-checkpoint', 'pages.heatmaps'] have duplicate paths

Traceback (most recent call last)
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 2464, in call
return self.wsgi_app(environ, start_response)
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 2450, in wsgi_app
response = self.handle_exception(e)
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 1867, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\hp\anaconda3\Lib\site-packages\flask_compat.py", line 39, in reraise
raise value
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 1945, in full_dispatch_request
self.try_trigger_before_first_request_functions()
File "C:\Users\hp\anaconda3\Lib\site-packages\flask\app.py", line 1993, in try_trigger_before_first_request_functions
func()
File "C:\Users\hp\anaconda3\Lib\site-packages\dash\dash.py", line 2268, in router
_validate.check_for_duplicate_pathnames(_pages.PAGE_REGISTRY)
File "C:\Users\hp\anaconda3\Lib\site-packages\dash_validate.py", line 435, in check_for_duplicate_pathnames
raise Exception(f"modules {modules} have duplicate paths")

charmeem · 2022-06-13T18:53:42Z

AnnMarieW · 2022-06-13T18:56:46Z

🤔 So, you see these errors when you run one of the apps from the github repo I shared the link to previously?

AnnMarieW · 2022-06-13T18:58:28Z

can you share the code you are running? It looks like there might be conflicts between "Histogram" and "Histogram-checkpoint" for example

charmeem · 2022-06-13T18:59:50Z

wait

charmeem · 2022-06-13T19:04:21Z

Yes I am running codes in multi_page_example_1

charmeem · 2022-06-13T19:09:16Z

app.py

import dash
import dash_bootstrap_components as dbc


app = dash.Dash(
    __name__, use_pages=True, external_stylesheets=[dbc.themes.BOOTSTRAP]
)

navbar = dbc.NavbarSimple(
    dbc.DropdownMenu(
        [
            dbc.DropdownMenuItem(page["name"], href=page["path"])
            for page in dash.page_registry.values()
            if page["module"] != "pages.not_found_404"
        ],
        nav=True,
        label="More Pages",
    ),
    brand="Multi Page App Plugin Demo",
    color="primary",
    dark=True,
    className="mb-2",
)

app.layout = dbc.Container(
    [navbar, dash.page_container],
    fluid=True,
)

if __name__ == "__main__":
    app.run_server(debug=True)

AnnMarieW · 2022-06-13T19:09:46Z

This looks odd:

Exception: modules ['pages..ipynb_checkpoints.heatmaps-checkpoint', 'pages.heatmaps'] have duplicate paths

Do you know where 'pages..ipynb_checkpoints.heatmaps-checkpoint might be coming from?

charmeem · 2022-06-13T19:10:14Z

histogram.py

from dash import Dash, dcc, html, Input, Output, callback
from dash import register_page
import plotly.express as px
import numpy as np

register_page(__name__)

np.random.seed(2020)

layout = html.Div(
    [
        html.P("Mean:"),
        dcc.Slider(
            id="histograms-mean", min=-3, max=3, value=0, marks={-3: "-3", 3: "3"}
        ),
        html.P("Standard Deviation:"),
        dcc.Slider(id="histograms-std", min=1, max=3, value=1, marks={1: "1", 3: "3"}),
        dcc.Graph(id="histograms-graph"),
    ]
)


@callback(
    Output("histograms-graph", "figure"),
    Input("histograms-mean", "value"),
    Input("histograms-std", "value")    
)
def display_color(mean, std):
    
    data = np.random.normal(mean, std, size=500)
    fig = px.histogram(data, nbins=30, range_x=[-10, 10])
    return fig

charmeem · 2022-06-13T19:14:38Z

It is now working.
ipynb_checkpoints was the directory automaticaly created by Jupyter note book. After removing that the code is wording fine.

Let me test with heatmaps.py page as well.

charmeem · 2022-06-13T19:16:57Z

All working now, Thanks for your hints.

AnnMarieW · 2022-06-13T19:18:17Z

oh, great - thanks! Now we'll know what to do for the next person who might have a similar issue 👍

charmeem · 2022-06-13T19:19:33Z

Can I close the case?

AnnMarieW · 2022-06-13T19:20:17Z

yes, please

charmeem · 2022-06-13T19:22:03Z

OK, appreciate the work you are doing designing this wonderful product, keep it up !

Damistar05 · 2023-05-03T16:18:18Z

Hi. Please am trying to deploy my link to render. But am getting errors: dash.exceptions.NoLayoutException: The layout was None at the time that run_server was called. Make sure to set the layout attribute of your application before running the server

alexcjohnson · 2023-05-03T16:39:13Z

Hi @Damistar05 - If you can post your code and your question on https://community.plotly.com/ there are lots of folks who will be happy to help!

AnnMarieW · 2023-05-03T16:39:14Z

Hi @Damistar05 - please don't use this version - this was a prototype used to develop the Dash Pages feature and is no longer being maintained. This feature is now part of Dash :-)

charmeem closed this as completed Jun 13, 2022

charmeem reopened this Jun 13, 2022

charmeem closed this as completed Jun 13, 2022

AnnMarieW mentioned this issue Jun 21, 2022

fixed pages to exclude files starting with . plotly/dash#2102

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ModuleNotFoundError: No module named 'pages.' #113

ModuleNotFoundError: No module named 'pages.' #113

charmeem commented Jun 13, 2022 •

edited by alexcjohnson

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ModuleNotFoundError: No module named 'pages.' #113

ModuleNotFoundError: No module named 'pages.' #113

Comments

charmeem commented Jun 13, 2022 • edited by alexcjohnson Loading

charmeem commented Jun 13, 2022

charmeem commented Jun 13, 2022 • edited by alexcjohnson Loading

Error:

histogram.py file:

charmeem commented Jun 13, 2022 • edited by alexcjohnson Loading

AnnMarieW commented Jun 13, 2022

charmeem commented Jun 13, 2022

AnnMarieW commented Jun 13, 2022

charmeem commented Jun 13, 2022

Secondly when I add a page 'heatmaps.py' in the /pages folder following error appears:

charmeem commented Jun 13, 2022

AnnMarieW commented Jun 13, 2022

AnnMarieW commented Jun 13, 2022

charmeem commented Jun 13, 2022

charmeem commented Jun 13, 2022

charmeem commented Jun 13, 2022

app.py

AnnMarieW commented Jun 13, 2022 • edited Loading

charmeem commented Jun 13, 2022

histogram.py

charmeem commented Jun 13, 2022

charmeem commented Jun 13, 2022

AnnMarieW commented Jun 13, 2022

charmeem commented Jun 13, 2022

AnnMarieW commented Jun 13, 2022

charmeem commented Jun 13, 2022

Damistar05 commented May 3, 2023

alexcjohnson commented May 3, 2023

AnnMarieW commented May 3, 2023

charmeem commented Jun 13, 2022 •

edited by alexcjohnson

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charmeem commented Jun 13, 2022 •

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