python 3.5 on Ubuntu 16.04 has dict syntax error for installed ackage?

Question

I'm struggling to understand this problem with python 3.5.2 on Ubuntu 16.04 with importlib_metadata package

An error has occured in the execution of the program. Error Message: invalid syntax (__init__.py, line 88)
Stack Trace: Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/jsonschema/__init__.py", line 31, in <module>
    from importlib import metadata
ImportError: cannot import name 'metadata'

During handling of the above exception, another exception occurred:


File "/usr/local/lib/python3.5/dist-packages/jsonschema/__init__.py", line 33, in <module>
    import importlib_metadata as metadata
File "/usr/local/lib/python3.5/dist-packages/importlib_metadata/__init__.py", line 88
    dist: Optional['Distribution'] = None
        ^
SyntaxError: invalid syntax

This importlib_metadata was installed:

pip3 install importlib-metadata --upgrade
Requirement already satisfied: importlib-metadata in /usr/local/lib/python3.5/dist-packages 
(3.3.0)
Requirement already satisfied: typing-extensions>=3.6.4 in /usr/local/lib/python3.5/dist- 
packages (from importlib-metadata) (3.7.4.3)
Requirement already satisfied: zipp>=0.5 in /usr/local/lib/python3.5/dist-packages (from 
importlib-metadata) (3.4.0)

Could anyone give some help to bypass this problem?

Answer 1

This got me today, very annoying issue.

Python 3.5.2, Ubuntu Xenial

One of the packages I was installing had a dependency of importlib-metadata , but the version wasn't pinned so I ended up with v3.7.0. This caused a problem, as v3.0.0 of importlib-metadata requires Python 3.6 or later .

However, I was able to pip3 install importlib-metadata==2.0.0 and then continue installing my other packages. This should work provided the package you are trying to install is compatible with 2.0.0 .

Answer 2

This package importlib-metadata is imported from a package jsonschema which I use, so I removed this dependent package of jsonschema package, and it works.

pip3 uninstall importlib-metadata