Repository navigation
Implement import by using importlib #958
Description
The standard library for Python contains importlib, which contains a pure* Python implementation of the import machinery. This is lucky as we then don't have to implement it all in Rust. But we have to bootstrap it and implement all of the functionality it uses from builtin modules.
This is blocked by the following:
- compile should accept bytes as well as strings
- _os.fspath - https://docs.python.org/3/library/os.html#os.fspath
- sys.implementation.cache_tag - This just needs to exist we don't support caching bytecode at the moment
- sys.pycache_prefix - same as above
- sys.flags
- str.endswith needs to support tuple argument
- _io.FileIO __enter__ and __exit__ methods
- sys.platform
- os.getcwd
- os.stat st_mtime attribute
- _warnings module
- possibly more
* Uses built-in module _imp to actually create module objects.
Reacted by Noa and 0jdxt
Activity
palaviv commentedon Jun 5, 2019
An initial implementation can be found in #1018.
palaviv commentedon Jun 7, 2019
Another thing that would help this is supporting
{!r}in string format.palaviv commentedon Jun 18, 2019
This can be closed not that #1018 was merged
apatrushev commentedon Jun 18, 2019
UPD: Related to #55
levelandglobalsargument is not provided and relative import is not working.As example
import unittestis broken at:Example:
module/__init__.py:module/second.py:Expected result
python -c 'import module; print(module.value)'Current result
cargo run -- -c 'import module; print(module.value)'apatrushev commentedon Jun 21, 2019
Additional investigation - CPython does level magic in compile:
python -c "import dis; dis.dis(compile('from .second import value', '', 'exec'))"(note second dot)
python -c "import dis; dis.dis(compile('from ..second import value', '', 'exec'))"palaviv commentedon Jun 21, 2019
@apatrushev please look at the implementation of the relative import at #1050.
apatrushev commentedon Jun 21, 2019
I took a short look on the code in PR. Unfortunately I have no strong opinion on where to place this code in compile or in vm execution because I am not confident neither in CPython code nor in RustPython. And I have no idea why CPython doing this in compile time - I just put my investigations here for the history to save the time later.
Besides this disclaimer your code LGTM (and
import unittestmoved forward!).palaviv commentedon Jun 30, 2019
@Skinny121, @apatrushev can we close this issue?