Python syntax in terminal with multiple python versions and os not working as expected

[PS101010]

Hello,

I tried using the example from the doc(techrep-2018.pdf) in the terminal.
I followed all obvious steps

• installed graphviz,
• installed fastidious,
• cloned zinc.git from github and extracted it,
• and added "." to path.

I used several python versions (3.5-3.9, with and without anaconda) on a virtual machine (easier & quicker to do this) and on a raspberry to exclude errors due to my specific build .
They all failed due to the same error codes (corresponding to python version,- independent of os).

I got the following copied terminal in/output:

Python 3.5

(py354) a@a:~$ pwd 
/home/a
(py354) a@a:~$ cd zinc
(py354) a@a:~/zinc$ python --version
Python 3.5.4 :: Anaconda, Inc.
(py354) a@a:~/zinc$ pip show fastidious
Name: fastidious
Version: 0.1.dev0
Summary: Yet another python parser generator
Home-page: https://github.com/lisael/fastidious
Author: lisael
Author-email: lisael@lisael.org
License: GPLv3
Location: /home/a/anaconda3/envs/py354/lib/python3.5/site-packages
Requires: 
(py354) a@a:~/zinc$ echo $PATH
/home/a/anaconda3/envs/py354/bin:/home/a/anaconda3/condabin:/home/a:/.local/bin:/usr/local
/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:.:/usr/games:/snap/bin
(py354) a@a:~/zinc$ python
Python 3.5.4 |Anaconda, Inc.| (default, Nov 20 2017, 18:44:38) 
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from zinc.nets import *
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "/home/a/zinc/zinc/nets.py", line 5, in <module>
  from .nodes import Node, Place, Transition
  File "/home/a/zinc/zinc/nodes.py", line 5, in <module>
  from .tokens import Token
  File "/home/a/zinc/zinc/tokens.py", line 39, in <module>
  class BlackToken (Token, enum.IntEnum) :
  File "/home/a/zinc/zinc/tokens.py", line 40, in BlackToken
  DOT = enum.auto()
 AttributeError: module 'enum' has no attribute 'auto'

Python 3.6

(py361-0) a@a:~/zinc$ pwd
/home/a/zinc
(py361-0) a@a:~/zinc$ python
Python 3.6.10 |Anaconda, Inc.| (default, Mar 25 2020, 23:51:54) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from zinc.nets import *
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "/home/a/zinc/zinc/nets.py", line 5, in <module>
 from .nodes import Node, Place, Transition
 File "/home/a/zinc/zinc/nodes.py", line 5, in <module>
 from .tokens import Token
 File "/home/a/zinc/zinc/tokens.py", line 39, in <module>
  class BlackToken (Token, enum.IntEnum) :
 File "/home/a/anaconda3/envs/py361-0/lib/python3.6/enum.py", line 197, in __new__
 enum_member = __new__(enum_class)
TypeError: object.__new__(BlackToken) is not safe, use int.__new__()

Python 3.7++-(3.9.0a6)

(py377) a@a:~/zinc$ python -V
Python 3.7.7
(py377) a@a:~/zinc$ pwd
/home/a/zinc
(py377) a@a:~/zinc$ echo $PATH
 /home/a/anaconda3/envs/py377/bin:/home/a/anaconda3/condabin:/home/a:/.local/bin:/usr/local
 /sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:.:/usr/games:/snap/bin
(py377) a@a:~/zinc$ pip show fastidious
Name: fastidious
Version: 0.1.dev0
Summary: Yet another python parser generator
Home-page: https://github.com/lisael/fastidious
Author: lisael
Author-email: lisael@lisael.org
License: GPLv3
Location: /home/a/anaconda3/envs/py377/lib/python3.7/site-packages
Requires: 
Required-by: 
(py377) a@a:~/zinc$ python
Python 3.7.7 (default, Mar 26 2020, 15:48:22) 
[GCC 7.3.0] :: Anaconda, Inc. on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from zinc.nets import *
>>> 
>>> net = PetriNet("Erathostene␣sieve", lang="python")
>>> 
>>> net.add_place(Place("p", ["2", "3", "4", "5", "6"], "int"))
WARNING:root:interpreted Python token '2' in p as source code "'2'"
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "/home/a/zinc/zinc/nodes.py", line 26, in __init__
  t = Token(repr(t))
 TypeError: Token() takes no arguments

After some searching I concluded that for the current module the requirement should be set to python 3.7++.
I haven't found any clue what I did wrong or why I get an errorcode for python 3.7.
Did I do something fundementally wrong in above steps or did the input syntax change?

After my research I think, that

• python 3.5 can't work due to the missing "auto"-helper inplementation
• in python 3.6 this happens as far as I understand it due to following change
  

I'd appreciate a very brief answer and in case of a changed syntax a short example.
In case of no obvious error I'd appreciate a short post about a working build with zinc

Thanks in advance for answering

P.S. If needed i can post logs with all installed packages instread of above abbreviated form