From b05b07fed174f8fbfa5a8632da917ad962c83bb8 Mon Sep 17 00:00:00 2001 From: Terry Jan Reedy Date: Tue, 23 Feb 2021 19:39:51 -0500 Subject: [PATCH] bpo-43283: Add IDLE doc paragraph about print speed (GH-24615) Printing to IDLE's Shell is often slower than printing to a system terminal, but it can be made faster by pre-formatting a single string before printing. (cherry picked from commit 2827e8a177c2a6584fada594bca6829c53a2872f) Co-authored-by: Terry Jan Reedy --- Doc/library/idle.rst | 9 +++++++++ Lib/idlelib/NEWS.txt | 4 ++++ Lib/idlelib/help.html | 10 +++++++++- .../next/IDLE/2021-02-21-16-30-10.bpo-43283.DLBwYn.rst | 3 +++ 4 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/IDLE/2021-02-21-16-30-10.bpo-43283.DLBwYn.rst diff --git a/Doc/library/idle.rst b/Doc/library/idle.rst index fc45e3161bc6d5..2b9bd4b5daaa77 100644 --- a/Doc/library/idle.rst +++ b/Doc/library/idle.rst @@ -726,6 +726,15 @@ with objects that get input from and send output to the Shell window. The original values stored in ``sys.__stdin__``, ``sys.__stdout__``, and ``sys.__stderr__`` are not touched, but may be ``None``. +Sending print output from one process to a text widget in another is +slower than printing to a system terminal in the same process. +This has the most effect when printing multiple arguments, as the string +for each argument, each separator, the newline are sent separately. +For development, this is usually not a problem, but if one wants to +print faster in IDLE, format and join together everything one wants +displayed together and then print a single string. Both format strings +and :meth:`str.join` can help combine fields and lines. + IDLE's standard stream replacements are not inherited by subprocesses created in the execution process, whether directly by user code or by modules such as multiprocessing. If such subprocess use ``input`` from diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt index 4bc4aefd1ac352..8374f7a582043b 100644 --- a/Lib/idlelib/NEWS.txt +++ b/Lib/idlelib/NEWS.txt @@ -3,6 +3,10 @@ Released on 2021-02-15? ====================================== +bpo-43283: Document why printing to IDLE's Shell is often slower than +printing to a system terminal and that it can be made faster by +pre-formatting a single string before printing. + bpo-23544: Disable Debug=>Stack Viewer when user code is running or Debugger is active, to prevent hang or crash. Patch by Zackery Spytz. diff --git a/Lib/idlelib/help.html b/Lib/idlelib/help.html index 1eefa506e2c8d9..924042d25b7bab 100644 --- a/Lib/idlelib/help.html +++ b/Lib/idlelib/help.html @@ -679,6 +679,14 @@

Running user codesys.__stdin__, sys.__stdout__, and sys.__stderr__ are not touched, but may be None.

+

Sending print output from one process to a text widget in another is +slower than printing to a system terminal in the same process. +This has the most effect when printing multiple arguments, as the string +for each argument, each separator, the newline are sent separately. +For development, this is usually not a problem, but if one wants to +print faster in IDLE, format and join together everything one wants +displayed together and then print a single string. Both format strings +and str.join() can help combine fields and lines.

IDLE’s standard stream replacements are not inherited by subprocesses created in the execution process, whether directly by user code or by modules such as multiprocessing. If such subprocess use input from @@ -982,7 +990,7 @@

Navigation



- Last updated on Feb 21, 2021. + Last updated on Feb 23, 2021. Found a bug?
diff --git a/Misc/NEWS.d/next/IDLE/2021-02-21-16-30-10.bpo-43283.DLBwYn.rst b/Misc/NEWS.d/next/IDLE/2021-02-21-16-30-10.bpo-43283.DLBwYn.rst new file mode 100644 index 00000000000000..7a627af412a8e3 --- /dev/null +++ b/Misc/NEWS.d/next/IDLE/2021-02-21-16-30-10.bpo-43283.DLBwYn.rst @@ -0,0 +1,3 @@ +Document why printing to IDLE's Shell is often slower than printing to a +system terminal and that it can be made faster by pre-formatting a single +string before printing.