Got "No module named 'dash_html_components'" although it is installed

Dash Python
1

I’m trying the example code from “basic dash callback”.

However, I got the following error:

❯ python3 test.py    
Traceback (most recent call last):
  File "test.py", line 3, in <module>
    import dash_html_components as html
ModuleNotFoundError: No module named 'dash_html_components'

I’m not sure why because I do have dash_html_components installed as shown below, and the python interpreter I’m using in vscode is set as “Python 3.8.12 64-bit (‘base’: conda)” already.

❯ conda list dash    
# packages in environment at /Users/USERNAME/opt/anaconda3:
#
# Name                    Version                   Build  Channel
dash                      2.0.0              pyhd8ed1ab_0    conda-forge
dash-core-components      1.15.0                   pypi_0    pypi
dash-html-components      1.1.2                    pypi_0    pypi
dash-renderer             1.9.0                    pypi_0    pypi
dash-table                4.11.2                   pypi_0    pypi
jupyter-dash              0.4.0              pyhd8ed1ab_0    conda-forge

Have I missed anything important here?

2

Allow me to reply myself:

This is caused by old versions of dash related packages.

  1. First, update both dash-core-components and dash-html-components to the latest version of 2.0.0:
pip install --upgrade dash-html-components
pip install --upgrade dash-core-components
  1. update the code to call the core and html components:
import dash
# import dash_core_components as dcc    #deprecated
from dash import dcc 
# import dash_html_components as html    #deprecated
from dash import html
from dash.dependencies import Input, Output

I hope the Dash documents can update the contents accordingly.

3

Glad you figure it out. Note that Input and Output can also be imported from dash directly. More info here.

1 Like
4

Very cool, thanks for the link on Dash 2.0 Migration.