Cannot install: No module named 'parser'

[ClayShoaf]

When I try to install, I get the following output:

[user ~/github/pycscope]$ python setup.py install
Traceback (most recent call last):
  File "/home/user/github/pycscope/setup.py", line 5, in <module>
    from pycscope import __version__
  File "/home/user/github/pycscope/pycscope/__init__.py", line 25, in <module>
    import keyword, parser, symbol, token
ModuleNotFoundError: No module named 'parser'

[ruben2020]

I think the issue is basically that pycscope cannot be run using Python 3.10 because the parser module has been removed. It works on Python 3.8 and older, though.

[portante]

Ugh.

[arkdae]

That's not the only thing that is gone in 3.10, so is the symbol module.

[brianphaley]

Hi Peter!

And at least one new distro (Ubuntu 22.04) is 3.10+ only now ;-( I guess ast is the closest replacement? I might have to start looking at this as I use it every day, until then can generate cscope.out files on an older system.

[portante]

Any help you can offer would be great. I have not had a chance to dive into this work for a long time now.

[ruben2020]

@portante The parser module has been deprecated since Python 3.10. The only way left is the ast (abstract syntax tree) module. However, I think pycscope requires a concrete syntax tree that preserves the original source code, rather than an abstract syntax tree that's lossy. So, instead of using the ast module, you may need something like LibCST.

[ruben2020]

@portante oh. I'm mistaken. There might be a far simpler way to fix this. Please see this page. The change looks trivial. They simply replaced parser.suite with ast.parse.

[ruben2020]

@portante I tried it, but it doesn't work. I think the old tuple structure is no longer used. Looks like you have no other choice but to port pycscope to ast or LibCST, which is a huge change to pycscope. It's almost a rewrite I expect. The other alternative is for you to get the old parser and symbol modules' source code from 3.9 and incorporate it into pycscope.

[xin3liang]

FYI, for Ubuntu users, maybe installing the older Python 3.9 as a workaround:

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update
sudo apt-get install python3.9 python3.9-venv
python3.9 -m venv ~/.venvs/py3.9
. ~/.venvs/py3.9/bin/activate
pip install ./pycscope

Reference: https://askubuntu.com/questions/682869/how-do-i-install-a-different-python-version-using-apt-get