Make sure all deprecated items in importlib raise `DeprecationWarning`

[brettcannon]

• importlib.abc.Loader
  • importlib.abc.InspectLoader.load_module()
  • importlib.abc.FileLoader.load_module()
  • importlib.abc.SourceLoader.load_module()
  • importlib.machinery.SourceFileLoader.load_module()
  • imortlib.machinery.SourcelessFileLoader.load_module()
• importlib.abc.ResourceLoader
• importlib.abc.SourceLoader.path_mtime()
• importlib.machinery.DEBUG_BYTECODE_SUFFIXES
• importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES
• debug_override parameter of importlib.util.cache_from_source()

Linked PRs

• gh-121604: Raise DeprecationWarnings in importlib #121765
• gh-121604: Make sure all deprecated items in importlib raise DeprecationWarning #128007
• gh-121604: fix ResourceLoader deprecation warning message #128859
• gh-121604: fix warnings in test_importlib.test_abc and test_importlib.test_windows #128904

[rashansmith]

I will try this one at europython :)

[tomasr8]

@rashansmith

To add deprecation warnings to module-level constants like DEBUG_BYTECODE_SUFFIXES I think you can use something like this:

cpython/Lib/calendar.py

Lines 44 to 54 in 4e36dd7

	def __getattr__(name):
	if name in ('January', 'February'):
	import warnings
	warnings.warn(f"The '{name}' attribute is deprecated, use '{name.upper()}' instead",
	DeprecationWarning, stacklevel=2)
	if name == 'January':
	return 1
	else:
	return 2
	raise AttributeError(f"module '{__name__}' has no attribute '{name}'")

[rashansmith]

@tomasr8 thanks, I've been looking at this exact file as a reference! Can you confirm which of the tasks are already done? For example in _abc.py, in the load_module() function I can already see a "# Warning implemented in _load_module_shim()." message.

[willingc]

Hi @brettcannon, I'm sitting at Europython sprints and working with @rashansmith. If you know if any of these have already been done, please let us know. Going to check the history :D

[bedevere-app]

GH-121765 is a backport of this pull request to the 3.14 branch.

[rashansmith]

@brettcannon @willingc @tomasr8 I've created a PR for this issue. Please let me know if it looks good or any issues I should resolve. It is based on validating which deprecationwarnings have already been implemented from the list, and therefore working on the remainders:

• importlib.abc.Loader
  • importlib.abc.InspectLoader.load_module() - already done
  • importlib.abc.FileLoader.load_module() - already done
  • importlib.abc.SourceLoader.load_module() - already done
  • importlib.machinery.SourceFileLoader.load_module() - already done
  • imortlib.machinery.SourcelessFileLoader - PR
• 
 importlib.abc.ResourceLoader PR
• 
 importlib.abc.SourceLoader.path_mtime() PR
• 
 importlib.machinery.DEBUG_BYTECODE_SUFFIXES PR
• 
 importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES PR
• 
 importlib.machinery.WindowsRegistryFinder PR
• 
 debug_override parameter of importlib.util.cache_from_source() - already done

[brettcannon]

@willingc @rashansmith I made the list from the docs based on a comment on another issue that made it sound like SourceFileLoader.load_module() wasn't raising an exception. I had not taken the time to verify anything. So thanks to @rashansmith for checking! I'll update the list based on what you found.