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Ask HN: Why Python relative import is so fundamentally broken?

Seems that relative import is implemented as relative to where the python.exe executed instead of the place where the file is. So the nature is depending on where you run the doctest or where you put your jupyter notebook, all imports inside the project will break!

stop50 3y ago
it was always meant as an helper: #a/__init__.py from .suba import A from .subb import B #script.py from a import A, B If you want to import local files you have to edit the module path to include the current directory.
- akasakahakada 3y ago
  This is flawed. I can have physics.core module and chemistry.core module. But if I add both into sys.path then import .core from physics directory, guess which core will be imported?
  - stop50 3y ago
    You usually get an import error. To import physics.core with an relative import you have to be physics/__init__.py
lordkrandel 3y ago
Python is born as a scripting language. Current directory is very important for this reason. You enter a folder and you launch your script with the current python version. Long before virtualenvs and pip itself.
ActorNightly 3y ago
Its not broken? Just like with everything, you have to understand semantics. If you are writing anything more than a single file, a.k.a a module that has directories and subdirectories, which you will import in another place, you are supposed to put everything into a package format and install it with pip install -e ./ Then, within the module are free to use the absolute imports starting with the module name, or relative ones, and it all works like a charm. The import system is designed around this. Alternatively, you can modify the PYTHONPATH env variable, or modify sys.path dynamically, to append to paths and import directly.
- akasakahakada 3y ago
  Relative import should be independent of package. One should be moving files around without rewriting all import headers.
  - aprdm 3y ago
    That's opinion, not a fact
aristofun 3y ago
If i say because python was poorly designed language in the first place (and still is pretty mediocre by 2023 devx standards) - people will downvote, because they got attached to the naked king too much.
- dev_0 3y ago
  [dead]
PurpleRamen 3y ago
> Seems that relative import is implemented as relative to where the python.exe executed instead of the place where the file is. That's not true, why do you think that? Relative Imports are anoying BS, but by default they do work based on the package-hierachy of the executed file, at least with normal Python. It could be there is something in your setup or handling of imports which changes this behaviour, as changing the import-mechnism is possible in python. > So the nature is depending on where you run the doctest or where you put your jupyter notebook, all imports inside the project will break! Maybe in those cases, the executed file is not what you think it is? So your top-level package is not located where your test is. Do you execute the test-file directly (python3 test.py), or do you use some starter-script (py.test test.py)?
- akasakahakada 3y ago
  > Relative Imports are anoying BS Anoying because someone 20years ago wrote this bug and no one is able to see and fix it. People derived many workarounds to deal with this flaw , but the design flaw remain unchanged.

stop50 3y ago

it was always meant as an helper: #a/__init__.py from .suba import A from .subb import B #script.py from a import A, B If you want to import local files you have to edit the module path to include the current directory.

akasakahakada 3y ago
This is flawed. I can have physics.core module and chemistry.core module. But if I add both into sys.path then import .core from physics directory, guess which core will be imported?
- stop50 3y ago
  You usually get an import error. To import physics.core with an relative import you have to be physics/__init__.py

lordkrandel 3y ago

Python is born as a scripting language. Current directory is very important for this reason. You enter a folder and you launch your script with the current python version. Long before virtualenvs and pip itself.

ActorNightly 3y ago

Its not broken? Just like with everything, you have to understand semantics. If you are writing anything more than a single file, a.k.a a module that has directories and subdirectories, which you will import in another place, you are supposed to put everything into a package format and install it with pip install -e ./ Then, within the module are free to use the absolute imports starting with the module name, or relative ones, and it all works like a charm. The import system is designed around this. Alternatively, you can modify the PYTHONPATH env variable, or modify sys.path dynamically, to append to paths and import directly.

akasakahakada 3y ago
Relative import should be independent of package. One should be moving files around without rewriting all import headers.
- aprdm 3y ago
  That's opinion, not a fact

aristofun 3y ago

If i say because python was poorly designed language in the first place (and still is pretty mediocre by 2023 devx standards) - people will downvote, because they got attached to the naked king too much.

dev_0 3y ago
[dead]

PurpleRamen 3y ago

> Seems that relative import is implemented as relative to where the python.exe executed instead of the place where the file is. That's not true, why do you think that? Relative Imports are anoying BS, but by default they do work based on the package-hierachy of the executed file, at least with normal Python. It could be there is something in your setup or handling of imports which changes this behaviour, as changing the import-mechnism is possible in python. > So the nature is depending on where you run the doctest or where you put your jupyter notebook, all imports inside the project will break! Maybe in those cases, the executed file is not what you think it is? So your top-level package is not located where your test is. Do you execute the test-file directly (python3 test.py), or do you use some starter-script (py.test test.py)?

akasakahakada 3y ago
> Relative Imports are anoying BS Anoying because someone 20years ago wrote this bug and no one is able to see and fix it. People derived many workarounds to deal with this flaw , but the design flaw remain unchanged.