# Error building dash-core-components for development **URL:** \ **Category:** Dash Python\ **Created:** [June 19, 2019, 2:29pm UTC](https://community.plotly.com/t/error-building-dash-core-components-for-development/24802 "2019-06-19T14:29:33Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![isemaj](https://avatars.discourse-cdn.com/v4/letter/i/d6d6ee/32.png) [@isemaj](https://community.plotly.com/u/isemaj)\ **Post date:** [June 19, 2019, 2:29pm UTC](https://community.plotly.com/t/error-building-dash-core-components-for-development/24802/1 "2019-06-19T14:29:33Z")
❗ **WARNING : English error ahead** 😃 I really want to contribute to `dash-core-compoents` and have some issue which I posted [here](https://community.plotly.com/t/cant-find-the-dash-generate-components-command/24675) but now I understand some of my mistake Here’s what I did during the process 1. `conda create -n dash_core python=3.7.3` 2. `conda activate dash_core` 3. `pip install dash` 4. `pip list -v` ```auto Package Version Location Installer -------------------- -------- -------------------------------------------------------------- --------- attrs 19.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip certifi 2019.3.9 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages chardet 3.0.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Click 7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash 0.43.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-core-components 0.48.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-html-components 0.16.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-renderer 0.24.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-table 3.7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip decorator 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask 1.0.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask-Compress 1.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip idna 2.8 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip ipython-genutils 0.2.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip itsdangerous 1.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Jinja2 2.10.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jsonschema 3.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jupyter-core 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip MarkupSafe 1.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip nbformat 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pip 19.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages plotly 3.10.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pyrsistent 0.15.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pytz 2019.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip requests 2.22.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip retrying 1.3.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip setuptools 41.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages six 1.12.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip traitlets 4.3.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip urllib3 1.25.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Werkzeug 0.15.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip wheel 0.33.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages ``` **NOTE** `dash-core-components` is always included when `dash` is installed via `pip` 1. `npm i` it runs the following script automatically ```auto > dash-core-components@0.48.0 prepare /home/qrs/Programming/Community/dash-core-components > npm run build > dash-core-components@0.48.0 build /home/qrs/Programming/Community/dash-core-components > npm run build:js && npm run build:py_and_r > dash-core-components@0.48.0 build:js /home/qrs/Programming/Community/dash-core-components > webpack --mode production ``` **NOTE :** I skipped the step 2 from [this CONTRIBUTING.md](https://github.com/plotly/dash-core-components/blob/master/README.md) which requires to run `npm run build` since it was run automatically after `npm i` 1. `python setup.py install` output (last few lines): ```auto byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/ __init__.py to __init__.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Interval.py to Interval.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Checklist.py to Checklist.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Markdown.py to Markdown.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Upload.py to Upload.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/ConfirmDialogProvider.py to ConfirmDialogProvider.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Tabs.py to Tabs.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/RadioItems.py to RadioItems.cpython-37.pyc byte-compiling build/bdist.linux-x86_64/egg/dash_core_components/Slider.py to Slider.cpython-37.pyc creating build/bdist.linux-x86_64/egg/EGG-INFO copying dash_core_components.egg-info/PKG-INFO -> build/bdist.linux-x86_64/egg/EGG-INFO copying dash_core_components.egg-info/SOURCES.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying dash_core_components.egg-info/dependency_links.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying dash_core_components.egg-info/top_level.txt -> build/bdist.linux-x86_64/egg/EGG-INFO zip_safe flag not set; analyzing archive contents... dash_core_components. __pycache__. __init__.cpython-37: module references __file__ creating 'dist/dash_core_components-0.48.0-py3.7.egg' and adding 'build/bdist.linux-x86_64/egg' to it removing 'build/bdist.linux-x86_64/egg' (and everything under it) Processing dash_core_components-0.48.0-py3.7.egg creating /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages/dash_core_components-0.48.0-py3.7.egg Extracting dash_core_components-0.48.0-py3.7.egg to /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages Adding dash-core-components 0.48.0 to easy-install.pth file Installed /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages/dash_core_components-0.48.0-py3.7.egg Processing dependencies for dash-core-components==0.48.0 Finished processing dependencies for dash-core-components==0.48.0 ``` 1. `pip list -v` **NOTE :** `dash-core-components` location doesn’t change ```auto Package Version Location Installer -------------------- -------- -------------------------------------------------------------- --------- attrs 19.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip certifi 2019.3.9 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages chardet 3.0.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Click 7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash 0.43.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-core-components 0.48.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-html-components 0.16.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-renderer 0.24.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-table 3.7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip decorator 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask 1.0.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask-Compress 1.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip idna 2.8 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip ipython-genutils 0.2.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip itsdangerous 1.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Jinja2 2.10.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jsonschema 3.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jupyter-core 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip MarkupSafe 1.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip nbformat 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pip 19.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages plotly 3.10.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pyrsistent 0.15.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pytz 2019.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip requests 2.22.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip retrying 1.3.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip setuptools 41.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages six 1.12.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip traitlets 4.3.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip urllib3 1.25.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Werkzeug 0.15.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip wheel 0.33.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages ``` Running the `my_dash_layout.py` works perfectly. 1. `python my_dash_layout.py` ```auto # my_dash_layout.py import dash import dash_core_components as dcc import dash_html_components as html external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css'] app = dash.Dash( __name__ , external_stylesheets=external_stylesheets) app.layout = html.Div(children=[ html.H1(children='Hello Dash'), html.Div(children=''' Dash: A web application framework for Python. '''), dcc.Graph( id='example-graph', figure={ 'data': [ {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'}, {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': u'Montréal'}, ], 'layout': { 'title': 'Dash Data Visualization' } } ) ]) if __name__ == ' __main__': app.run_server(debug=True) ``` ![pl1](https://us1.discourse-cdn.com/flex024/uploads/plot/original/2X/f/fc947bcc95d620395b78345e8cf7ac621e33028f.png) But uninstalling `dash-core-components` to use my local “copy” of `dash-core-components` shows a `FileNotFoundError`. 1. `pip uninstall dash_core_components` 2. `pip list -v` ```auto Package Version Location Installer -------------------- -------- ---------------------------------------------------------------------------------------------------- --------- attrs 19.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip certifi 2019.3.9 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages chardet 3.0.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Click 7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash 0.43.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-core-components 0.48.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages/dash_core_components-0.48.0-py3.7.egg dash-html-components 0.16.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-renderer 0.24.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip dash-table 3.7.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip decorator 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask 1.0.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Flask-Compress 1.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip idna 2.8 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip ipython-genutils 0.2.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip itsdangerous 1.1.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Jinja2 2.10.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jsonschema 3.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip jupyter-core 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip MarkupSafe 1.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip nbformat 4.4.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pip 19.1.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages plotly 3.10.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pyrsistent 0.15.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip pytz 2019.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip requests 2.22.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip retrying 1.3.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip setuptools 41.0.1 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages six 1.12.0 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip traitlets 4.3.2 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip urllib3 1.25.3 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip Werkzeug 0.15.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages pip wheel 0.33.4 /home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages ``` **NOTE :** the location now shows the local “copy” of `dash_core_components` that was installed via `python setup.py install` Running the `my_dash_layout.py` now shows an error about the missing file `highlight.pack.js`. 1. `python my_dash_layout.py` ```auto FileNotFoundError: [Errno 2] No such file or directory: '/home/qrs/anaconda3/envs/dash_core/lib/python3.7/site-packages/dash_core_components-0.48.0-py3.7.egg/dash_core_components/highlight.pack.js' ``` ![Screenshot%20from%202019-06-19%2022-36-42](https://us1.discourse-cdn.com/flex024/uploads/plot/original/2X/8/84281bea5e5f7efed7121ec5bafeb5dff7913b00.png)