Dash: [BUG] dash doesn't get imported when a file named "org.py", "dash.py", or "test.py" with specific content is present in the current directory // "AttributeError: module 'dash' has no attribute 'Dash'"

[cannatag]

Describe your context

dash (1.9.1)
dash-core-components (1.8.1)
dash-html-components (1.0.2)
dash-renderer (1.2.4)
dash-table (4.6.1)

Describe the bug

If a file named org.py is present in the current directory with the following content:

import dash_core_components as dcc

then dash doesn't import and I get the following message:

>>> import dash
Dash was not successfully imported. Make sure you don't have a file named
'dash.py' in your current directory.

Expected behavior
dash should import without any error.

Additional info

• The org.py is never imported
• If I rename the file to a different name dash get imported without any problem.
• The problem is shown also with ``import dash_html_components as html```
• The problem is shown either on Windows and in Linux
• Tested with python3.4, python3.6, python3.8

Steps to replicate the problem on Linux

$ mkdir mytest
$ cd mytest
$ echo "import dash_core_components as dcc" > org.py
$ python3 -m venv venv
$ . venv/bin/activate
(venv) $ pip install dash
(venv) $ python
Python 3.4.6 (default, Mar 01 2017, 16:52:22) [GCC] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dash
Dash was not successfully imported. Make sure you don't have a file named
'dash.py' in your current directory.
(venv) $

if I rename the file the import works:

(venv) $ mv org.py othername.py
(venv) $ python
Python 3.4.6 (default, Mar 01 2017, 16:52:22) [GCC] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dash
>>>

[Charlenator]

I had the exact same issue with a file named "test.py"

[alexcjohnson]

OK this one is very weird... it appears to come from the pickle module:

# Jython has PyStringMap; it's a dict subclass with string keys
try:
    from org.python.core import PyStringMap
except ImportError:
    PyStringMap = None

Which you can see if you raise an error inside org.py - it is trying to import it, to find org.python.core

That seems like a terribly hacky bit of code to have living in the Python core, but we'll have to live with that part. This becomes a problem when org.py tries to import something that itself needs dash (in this case dash_core_components) and finds a partially-initialized module. I suppose we could put something unique very early in the dash __init__.py (something like __plotly_dash__ = True) and short-circuit the "Make sure you don't have a file named 'dash.py' in your current directory." errors if we find it.

I don't see a problem with test.py but if we make a generic fix like ^^ it should cover any related oddities.

[meltbox360]

Exact same issue with test.py
For some reason downgrading to dash 1.12.0 or lower also fixed the issue. I cannot for the life of me find why though.

[alexcjohnson]

@meltbox360 can you try raising an exception at the top of test.py and post the traceback you see?

[meltbox360]

Traceback (most recent call last):
  File "C:/Users/xxx/PycharmProjects/plotGPS_OSM/Legacy/test6.py", line 14, in <module>
    import dash
  File "C:\Users\xxx\Anaconda3\envs\OSMNX and Dash\lib\site-packages\dash\__init__.py", line 1, in <module>
    from .dash import Dash, no_update  # noqa: F401
  File "C:\Users\xxx\Anaconda3\envs\OSMNX and Dash\lib\site-packages\dash\dash.py", line 15, in <module>
    from future.moves.urllib.parse import urlparse
  File "C:\Users\kprzybys\Anaconda3\envs\OSMNX and Dash\lib\site-packages\future\moves\__init__.py", line 8, in <module>
    import_top_level_modules()
  File "C:\Users\xxx\Anaconda3\envs\OSMNX and Dash\lib\site-packages\future\standard_library\__init__.py", line 810, in import_top_level_modules
    with exclude_local_folder_imports(*TOP_LEVEL_MODULES):
  File "C:\Users\xxx\Anaconda3\envs\OSMNX and Dash\lib\site-packages\future\standard_library\__init__.py", line 781, in __enter__
    module = __import__(m, level=0)
  File "C:\Users\xxx\PycharmProjects\plotGPS_OSM\Legacy\test.py", line 1, in <module>
    raise Exception("TEST")
Exception: TEST

Process finished with exit code 1

[meltbox360]

Good call. I think test is a reserved module name in python see standard_library __init__.py ~line 800 probably

TOP_LEVEL_MODULES = ['builtins',
                     'copyreg',
                     'html',
                     'http',
                     'queue',
                     'reprlib',
                     'socketserver',
                     'test',
                     'tkinter',
                     'winreg',
                     'xmlrpc',
                     '_dummy_thread',
                     '_markupbase',
                     '_thread',
                    ]

Still have no idea why this works with 1.12.0 and before though.
I also have no idea if what I said above is true. Relatively new to python and haven't learned it too well yet.

[alexcjohnson]

Thanks @meltbox360 that's perfect. Haha with exclude_local_folder_imports(*TOP_LEVEL_MODULES) obviously didn't accomplish its goal, as test is in your local folder 🤔 It's also puzzling to me why I don't see the same issue with test via future, maybe exclude_local_folder_imports does the right thing on Mac but not on Windows? Anyway normally it should be fine to make a module named test. There does seem to be a built-in test module but the docs strongly discourage its use so I have no idea why future would reference it. But this is indeed the same issue as org so should the same fix should work.

[amirdora]

rename file test.py to something else

for it was caused by my file name which i named "test.py".

[chriddyp]

For folks googling, I believe this error also appears in the form "AttributeError: module 'dash' has no attribute 'Dash'"

[eric-spitler]

Tested Version = 1.16.3
https://pypi.org/project/dash/1.16.3/

In my case, there is no org.py, test.py, or dash.py, but my service does have test/__init__.py.

When I rename test/ to tests/, the error goes away. There was also a separate, unrelated dependency that I was installing that included its own test package in its wheel, thus still allowing import test to do something, and therefore prevent import dash.

Basically, for me to get functional I needed to ensure the application cannot perform import test, at which point import dash works.

[np-8]

Could this be prevented by just making dash to check if there is any test.py, or test folder, or org.py etc. in the folder where the application starts? And then raise and Exception with notification that your app will not work if you have files/folders named like this?

[shenshan]

Same issue with my script named code.py