Issue #13150: sysconfig no longer parses the Makefile and config.h files
when imported, instead doing it at build time. This makes importing
sysconfig faster and reduces Python startup time by 20%.
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 6594104..36c7aa4 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -319,9 +319,11 @@
config_dir_name = 'config'
return os.path.join(get_path('stdlib'), config_dir_name, 'Makefile')
-
-def _init_posix(vars):
- """Initialize the module as appropriate for POSIX systems."""
+def _generate_posix_vars():
+ """Generate the Python module containing build-time variables."""
+ import pprint
+ vars = {}
+ destfile = os.path.join(os.path.dirname(__file__), '_sysconfigdata.py')
# load the installed Makefile:
makefile = get_makefile_filename()
try:
@@ -346,7 +348,15 @@
# the scripts are in another directory.
if _PYTHON_BUILD:
vars['LDSHARED'] = vars['BLDSHARED']
+ with open(destfile, 'w', encoding='utf8') as f:
+ f.write('build_time_vars = ')
+ pprint.pprint(vars, stream=f)
+def _init_posix(vars):
+ """Initialize the module as appropriate for POSIX systems."""
+ # _sysconfigdata is generated at build time, see _generate_posix_vars()
+ from _sysconfigdata import build_time_vars
+ vars.update(build_time_vars)
def _init_non_posix(vars):
"""Initialize the module as appropriate for NT"""
@@ -753,6 +763,9 @@
def _main():
"""Display all information sysconfig detains."""
+ if '--generate-posix-vars' in sys.argv:
+ _generate_posix_vars()
+ return
print('Platform: "%s"' % get_platform())
print('Python version: "%s"' % get_python_version())
print('Current installation scheme: "%s"' % _get_default_scheme())