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Agreed. Java injection frameworks are opaque and accomplish what they need to with overly powerful mechanisms because of the nature of the language. You don't s

Agreed. Java injection frameworks are opaque and accomplish what they need to with overly powerful mechanisms because of the nature of the language. You don't see that sort of nonsense in python.

kaba0 3y ago
Wtf, so what do you think Django is?
- bb88 3y ago
  I'm curious to understand what dependency injection is in Django that you're referring to? I know pytest does DI with fixtures, and trying to figure out what you're pulling into a test can be difficult.
  - matsemann 3y ago
    In django you're importing a default cache, a default storage etc, and write your code to the interface. In settings.py you wire it all up. It's basically the same, for testing you would have to mock the import or provide some implementation.
    - raziel2p 3y ago
      technically that's not dependency injection, but a global service locator.
      - bb88 3y ago
        Yeah I agree on that here. The user doesn't write DI code for Django Class Based views. E.g. the view doesn't accept a Database upon instantiation.
za3faran 3y ago
Nothing to do with the nature of the language, but with the nature of the program. If you're writing a few line script, you don't need a DI container. Once your program gets large, it becomes extremely messy without one. It's no surprise projects like [1] exist. [1] https://github.com/ets-labs/python-dependency-injector https://github.com/ets-labs/python-dependency-injector
- bb88 3y ago
  That DI library is not pythonic at all. There's nothing wrong with this at all, say: class MyClass: def __init__(self, my_dep1=None): if my_dep1 is None: self.my_dep1 = get_my_dep1() # Or potentially raise else: self.my_dep1 = my_dep1 [...] Then to test: def test_my_class(): mocked_dep1 = MagicMock() my_class = MyClass(my_dep1=mocked_dep1) [...]
  - za3faran 3y ago
    And if you want to configure the scope of `my_dep1` (singleton, transient, etc.)? What about nested dependencies? etc.
    - bb88 3y ago
      Why do I care about any of that while writing python? Those seem like artifacts of a Java based DI system.
      - za3faran 3y ago
        It's a reality of any non-trivial program, regardless of the language.
        bb88 3y ago
        No. Some languages don't require you to play cat and mouse games to get around artificial limitations put there by the language designers. There was a talk at PyCon a while back about that patterns commonly used in Java were non-existent in Python.

Agreed. Java injection frameworks are opaque and accomplish what they need to with overly powerful mechanisms because of the nature of the language. You don't see that sort of nonsense in python.

kaba0 3y ago

Wtf, so what do you think Django is?

bb88 3y ago
I'm curious to understand what dependency injection is in Django that you're referring to? I know pytest does DI with fixtures, and trying to figure out what you're pulling into a test can be difficult.
- matsemann 3y ago
  In django you're importing a default cache, a default storage etc, and write your code to the interface. In settings.py you wire it all up. It's basically the same, for testing you would have to mock the import or provide some implementation.
  - raziel2p 3y ago
    technically that's not dependency injection, but a global service locator.
    - bb88 3y ago
      Yeah I agree on that here. The user doesn't write DI code for Django Class Based views. E.g. the view doesn't accept a Database upon instantiation.

za3faran 3y ago

Nothing to do with the nature of the language, but with the nature of the program. If you're writing a few line script, you don't need a DI container. Once your program gets large, it becomes extremely messy without one. It's no surprise projects like [1] exist. [1] https://github.com/ets-labs/python-dependency-injector https://github.com/ets-labs/python-dependency-injector

bb88 3y ago
That DI library is not pythonic at all. There's nothing wrong with this at all, say: class MyClass: def __init__(self, my_dep1=None): if my_dep1 is None: self.my_dep1 = get_my_dep1() # Or potentially raise else: self.my_dep1 = my_dep1 [...] Then to test: def test_my_class(): mocked_dep1 = MagicMock() my_class = MyClass(my_dep1=mocked_dep1) [...]
- za3faran 3y ago
  And if you want to configure the scope of `my_dep1` (singleton, transient, etc.)? What about nested dependencies? etc.
  - bb88 3y ago
    Why do I care about any of that while writing python? Those seem like artifacts of a Java based DI system.
    - za3faran 3y ago
      It's a reality of any non-trivial program, regardless of the language.
      - bb88 3y ago
        No. Some languages don't require you to play cat and mouse games to get around artificial limitations put there by the language designers. There was a talk at PyCon a while back about that patterns commonly used in Java were non-existent in Python.