Mapping and DataFrame demo apps through errors

Summary

While going through the demos provided in hello app I have encountered problems with two out of four (Mapping and DataFrame demo apps) through errors.

Steps to reproduce

1. mkvirtualenv streamllit
2. pip install streamlit
3. streamlit hello
4. Click on Mapping Demo or DataFrame Demo

Expected behavior:

I would expect demos would be shown in the right pain. It works as expected for the first two apps (Animation and Plotting Demo).

Actual behavior:

I get notifications, first

Streamlit cannot hash an object of type <class 'os._Environ'>.,
...

and then 6 of these

Streamlit failed to hash an object of type <class 'function'>.,
...

and at the end there is a traceback:

TypeError: object supporting the buffer API required
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/ScriptRunner.py", line 306, in _run_script exec(code, module.__dict__)
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/hello.py", line 334, in <module> run()
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/hello.py", line 308, in run demo()
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/hello.py", line 78, in mapping_demo "data": from_data_file("bike_rental_stats.json"),
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/caching.py", line 544, in wrapped_func return get_or_set_cache()
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/caching.py", line 509, in get_or_set_cache code_hasher.update(func)
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/hashing.py", line 185, in update self._update(self.hasher, obj, context)
File "/home/vaidas/.virtualenvs/streamlit/lib/python3.6/site-packages/streamlit/hashing.py", line 217, in _update hasher.update(b)

Is this a regression?

Tried to launch it for the first time.

Debug info

• Streamlit version: 0.47.4
• Python version: Python 3.6.8
• Using virtualenv with virtualenvwrapper
• OS version: Ubuntu 18.04
• Browser version: Chrome Version 77.0.3865.90

[rock3125]

same error; Streamlit, version 0.47.4 Ubuntu 18.10 Python 3.6.8

However - trying python 2.7.15+ on the same OS DID work!

So it looks like they’ve tested it on Python 2 mostly and not really done much running on Python 3. Shame, considering Python 2 will reach the end of its life on January 1st, 2020.

[tvst]

Agreed with @roycoding. This looks like a dupe of #242. (Thanks Roy!)

The fix is coming soon with PR #254

(Closing this as a duplicate. Please reopen if you think this is not right)