Improve import time of various stdlib modules #118761
Description
Feature or enhancement
Proposal:
Following on from #109653, further improvements can be made to import times.
Links to previous discussion of this feature:
For example:
importlib.metadata is often used for tasks that need to happen at import, e.g. to enumerate/load entry point plug-ins, so it might be worth seeing if we can cut down its own import time a bit more.
importlib.metadata imports zipfile at the top for a function that won't be called in the vast majority of cases. It also imports importlib.abc, which in turn imports importlib.resources, to subclass an ABC with a single, non-abstract method - I assume redefining the method in importlib.metadata would be harmless. Some other less frequently-used imports which are only accessed once or twice, such as json, could also be tucked away in their calling functions.
Linked PRs
- gh-118761: Improve import time of
pprint#122725 - gh-118761: Speedup pathlib import by deferring shutil #123520
- gh-121423: Improve import time of
socketby writingsocket.errorTabas a constant and lazy import modules #121424 - gh-118761: Improve import time of
mimetypes#126979 - gh-118761: improve import time for
pickle#128732 - gh-118761: substitute
reimport inbase64.b16decodefor a more efficient alternative #128736 - gh-118761: improve import time for
secrets#128738 - gh-118761: Improve import time for
csv#128858 - gh-118761: Reduce import time of gettext.py by delaying re import #128898
- gh-118761: improve optparse import time by delaying textwrap import #128899
- gh-118761: Improve import time of
tomllib#128907 - gh-118761: Improve import time for
pstatsandzipfileby removing imports totyping#128981 - gh-118761: Improve import time of
sqlite3#129118 - gh-118761: Improve import time of
subprocess#129427 - gh-118761: Always lazy import
warningsinthreading#129428 - [3.13] gh-118761: Improve import time of
subprocess(GH-129427) #129447 - [3.12] gh-118761: Improve import time of
subprocess(GH-129427) #129448 - gh-118761: Improve import time by lazy import of
warnings#129765 - gh-118761: Improve import time by lazy import of
traceback#129811 - gh-118761: Always lazy import
reinlocale#129860 - gh-118761: Improve import time of
dataclasses#129925 - gh-118761: Improve import time of
cmdmodule #130056 - gh-118761: Revert "Improve import time of
subprocess(GH-129427)" #130201 - [3.13] gh-118761: Revert "Improve import time of
subprocess(GH-129427)" (GH-130201) #130204 - [3.12] gh-118761: Revert "Improve import time of
subprocess(GH-129427)" (GH-130201) #130205 - gh-137855: Improve import time of
sqlite3#131796 - gh-118761: Optimise import time for ast #131953
- gh-137855: Optimise import time for textwrap #131956
- gh-118761: Fix star-import of
ast#132024 - gh-118761: Fix star-import of ast (alternative) #132025
- gh-118761: Improve import time of
annotationlib#132028 - gh-118761: Use
enum._simple_enumforannotationlib.Format#132031 - gh-118761: Cover the import time optimisations in What's New #132035
- gh-118761: Optimise import time for
shlex#132036 - gh-118761: Optimise import time for
string#132037 - gh-137855:
email.quoprimimeremovingreimport #132046 - gh-118761: Defer import of functools in annotationlib #132059
- gh-118761: Lazily import annotationlib in typing #132060
- GH-118761: Expose more core interpreter types in
_types#132103 - gh-118761: Add helper to ensure that lazy imports are actually lazy #132614
- gh-118761: Add test_lazy_import for more modules #133057