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gh-137855: Improve import time of sqlite3#131796

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Wulian233 wants to merge 8 commits into from
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gh-137855: Improve import time of sqlite3#131796

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4b04bdf
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Wulian233 Mar 27, 2025
d3cf658
Improve the import time of `sqlite3` by 1.5x faster.
Wulian233 Jun 6, 2025
4373d47
Merge branch 'main' into sqlite
Wulian233 Jun 6, 2025
def1974
fix & finish
Wulian233 Jun 6, 2025
04eedab
Update dbapi2.py
Wulian233 Jun 6, 2025
ccf3575
fix
Wulian233 Jun 6, 2025
4c138d8
Merge branch 'python:main' into sqlite
Wulian233 Aug 17, 2025
f434be3
Rename gh-137855
Wulian233 Aug 17, 2025
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5 changes: 3 additions & 2 deletions Lib/sqlite3/__main__.py
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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,9 +7,7 @@
import sqlite3
import sys

from argparse import ArgumentParser
from code import InteractiveConsole
from textwrap import dedent
from _colorize import get_theme, theme_no_color

from ._completer import completer
Expand DownExpand Up@@ -86,6 +84,9 @@ def runsource(self, source, filename="<input>", symbol="single"):


def main(*args):
from argparse import ArgumentParser
from textwrap import dedent

Comment on lines 86 to +89
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@eli-schwartzeli-schwartzJun 6, 2025

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I do not see a valid reason to do code churn and delay imports for the sake of speeding up import sqlite3.__main__ while assuming that sqlite3.__main__.main() is never called.

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@terryjreedyterryjreedyAug 16, 2025

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I presume the following: execute is used by the REPL in addition to CLI; user code could import to use SQLiteInteractiveConsole. Whether worth it, not my call.

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@eli-schwartzeli-schwartzAug 17, 2025

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The REPL is of course part of calling main(), which makes my point quite well. :)

User code certainly could import SQLiteInteractiveConsole, as it lies within their technical capability. I think any user code importing an interactive console from a module named __main__ ought to be prepared to use it without worrying about the startup time of importing argparse and textwrap. A module called __main__ feels rather special to me in that sense -- one ought not casually resort to importing it.

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@serhiy-storchakaserhiy-storchakaAug 17, 2025

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I agree with @eli-schwartz. This change looks meaningless.

parser = ArgumentParser(
description="Python sqlite3 CLI",
color=True,
Expand Down
6 changes: 5 additions & 1 deletion Lib/sqlite3/dbapi2.py
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Expand Up@@ -21,7 +21,6 @@
# 3. This notice may not be removed or altered from any source distribution.

import datetime
import time
import collections.abc

from _sqlite3 import *
Expand All@@ -37,12 +36,15 @@
Timestamp = datetime.datetime

def DateFromTicks(ticks):
import time # Lazy, to improve import time
return Date(*time.localtime(ticks)[:3])

def TimeFromTicks(ticks):
import time # Lazy, to improve import time
return Time(*time.localtime(ticks)[3:6])

def TimestampFromTicks(ticks):
import time # Lazy, to improve import time
return Timestamp(*time.localtime(ticks)[:6])


Expand All@@ -52,6 +54,8 @@ def TimestampFromTicks(ticks):
collections.abc.Sequence.register(Row)

def register_adapters_and_converters():
global _lazy_register
_lazy_register = lambda: None # Prevent multiple registration # noqa: E731
from warnings import warn

msg = ("The default{what} is deprecated as of Python 3.12; "
Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Library/2025-01-21-14-51-44.gh-issue-137855.Z0F-d5.rst
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@@ -0,0 +1 @@
Improve the import time of :mod:`sqlite3` by 1.5x faster.
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