[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

STINNER Victor added the comment: I created bpo-36945: "Add _PyPreConfig.configure_locale: allow to leave LC_CTYPE unchanged when embedding Python". -- ___ Python tracker

[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

Christoph Gohlke added the comment: This is still an issue with Python 3.8.0a4 -- components: +Windows nosy: +paul.moore, steve.dower, tim.golden, zach.ware versions: +Python 3.8 ___ Python tracker

[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

Dragoljub added the comment: Do we know if its possible to prevent the initialize LC_CTYPE on startup? Is there some combination of ENV-Var or CMD-Args that can avoid this slowdown on Windows? What are the next step to get the issue assigned? --

[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

Dragoljub added the comment: This is the default LC_CTYPE locale type I see on Windows10 and Python 3.7.1 vs 3.5.2: Same: 'C' '3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 14:57:15) [MSC v.1915 64 bit (AMD64)]' import _locale _locale.setlocale(_locale.LC_CTYPE, None) 'C' '3.5.2

[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

Dragoljub added the comment: On Python 3.7.1 and Windows 10: I attempted locale.setlocale(locale.LC_ALL, "POSIX") --> Errors Out --- Error Traceback (most recent call last) in > 1

[issue35195] [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit()

Change by STINNER Victor : -- title: Pandas read_csv() is 3.5X Slower on Python 3.7.1 vs Python 3.6.7 & 3.5.2 On Windows 10 -> [Windows] Python 3.7 initializes LC_CTYPE locale at startup, causing performance issue on msvcrt isdigit() ___ Python