From 7cb11fa89034a06dcad58b65a0321dae9171dbea Mon Sep 17 00:00:00 2001 From: Antoine Pitrou Date: Thu, 24 Oct 2013 22:23:42 +0200 Subject: [PATCH] Close #19379: Lazily import linecache in the warnings module, to make startup with warnings faster until a warning gets printed. --- Lib/warnings.py | 6 ++---- Misc/NEWS | 3 +++ 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/Lib/warnings.py b/Lib/warnings.py index b05a08ee83..a427e3510e 100644 --- a/Lib/warnings.py +++ b/Lib/warnings.py @@ -1,9 +1,5 @@ """Python part of the warnings subsystem.""" -# Note: function level imports should *not* be used -# in this module as it may cause import lock deadlock. -# See bug 683658. -import linecache import sys __all__ = ["warn", "showwarning", "formatwarning", "filterwarnings", @@ -21,6 +17,7 @@ def showwarning(message, category, filename, lineno, file=None, line=None): def formatwarning(message, category, filename, lineno, line=None): """Function to format a warning the standard way.""" + import linecache s = "%s:%s: %s: %s\n" % (filename, lineno, category.__name__, message) line = linecache.getline(filename, lineno) if line is None else line if line: @@ -233,6 +230,7 @@ def warn_explicit(message, category, filename, lineno, # Prime the linecache for formatting, in case the # "file" is actually in a zipfile or something. + import linecache linecache.getlines(filename, module_globals) if action == "error": diff --git a/Misc/NEWS b/Misc/NEWS index 69cb09457c..52c86907f4 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -21,6 +21,9 @@ Core and Builtins Library ------- +- Issue #19379: Lazily import linecache in the warnings module, to make + startup with warnings faster until a warning gets printed. + - Issue #19327: Fixed the working of regular expressions with too big charset. - Issue #17400: New 'is_global' attribute for ipaddress to tell if an address -- 2.49.0