Fail to import dash

Dash Python
1

After running the code, it shows the message of: “Fail to import DASH, make sure there is no same file dash.py in this directory”.
This code is able to run on my another PC. the difference is I install dash and other components by using tar.gz file instead of install directly by “pip install dash”.

2

Can you see dash listed when you type

python -m pip list

?

3

yes, i checked, there is dash (version 1.13.4) in the list

4

do you have a python file called “dash.py” where you have written code?

5

Also check if you have a folder called dash among your python code. (More specifically, inside a folder listed in sys.path, apart from the dash in your site-packages)

Here’s a small script that can tell that if there are more than one dash folder or dash.py files in your PATH:
(save as for examplefinddash.py in same folder as your app.py and run)

from pathlib import Path
import sys

results = []


def get_dash_files_and_folders(rootfolder, results):
    for item in rootfolder.glob('*'):
        if item.name == 'dash.py':
            results.append(item)
        if not item.is_dir():
            continue
        if item.name == 'dash':
            results.append(item)
    return results


for item in sys.path:
    item = Path(item)
    if not item.is_dir():
        continue
    results = get_dash_files_and_folders(item, results)

if results:
    print('Found following files & folders:')
    print(results)
else:
    print('No dash found in sys.path!')
6

I only found the dash.py under: C:/users/XX/Anaconda3/lib/site-packages/dash
this is not the same folder I ran the app.py, and similar dash.py exist on my another laptop, but I am able to run in that one…

Thank you very much!

7

Like @fohrloop said, it’s probably because your have a dash.py file or a dash folder somewhere. Those should have different names because they are confusing the system. I would recommend using a separate virtual environment for your project.

Try this tutorial to start.

If you’re not interested in using JupiterDash, just watch the first part.

8

Thank you for your suggestion, and training video
I tested virtual environment today, and found following:

  1. With following sentence I still have the warming of "Dash was not successfully imported. Make sure you dont have a file named “dash.py” in your current directory. Tried the finddash code and find dash.py under the site-packages folder only
    import dash
    import dash_core_components as dcc
    import dash_html_components as html

  2. But if I have only: “import dash” in my code (delete import dcc and html), it will show only that: name ‘html’ is not defined…

9

We’re getting some other reports that this may be version dependent and introduced in 1.13.x. We are so far unable to reproduce on our end.

@jie - Could you try downgrading to 1.12.0 or 1.11.0 and see if the error remains? If so, then this a bug with something we did recently rather than the dash.py-style of issue that we usually see.

Thanks to everyone who is helping out diagnose this issue!

10

Hi, I downgrade dash to version 1.10.0, and it works now. Thank you very much!!

11

You may have a test.py in your directory. I had one and got the same error. I removed it and it works fine.

12

hi, thank you for your suggestion. I downgrade the Dash to lower version, it works.