New submission from Serhiy Storchaka: Since argparse becomes more used as standard way of parsing command-line arguments, the number of imports involved when import argparse becomes more important. Proposed patch reduces that number by 10 modules.
Unpatched: $ ./python -c 'import sys; s = set(sys.modules); import argparse; print(len(s), len(sys.modules), len(set(sys.modules) - s)); print(sorted(set(sys.modules) - s))' 35 65 30 ['_collections', '_functools', '_heapq', '_locale', '_operator', '_sre', '_struct', 'argparse', 'collections', 'collections.abc', 'copy', 'copyreg', 'enum', 'functools', 'gettext', 'heapq', 'itertools', 'keyword', 'locale', 'operator', 're', 'reprlib', 'sre_compile', 'sre_constants', 'sre_parse', 'struct', 'textwrap', 'types', 'warnings', 'weakref'] $ ./python -S -c 'import sys; s = set(sys.modules); import argparse; print(len(s), len(sys.modules), len(set(sys.modules) - s)); print(sorted(set(sys.modules) - s))' 23 61 38 ['_collections', '_collections_abc', '_functools', '_heapq', '_locale', '_operator', '_sre', '_stat', '_struct', 'argparse', 'collections', 'collections.abc', 'copy', 'copyreg', 'enum', 'errno', 'functools', 'genericpath', 'gettext', 'heapq', 'itertools', 'keyword', 'locale', 'operator', 'os', 'os.path', 'posixpath', 're', 'reprlib', 'sre_compile', 'sre_constants', 'sre_parse', 'stat', 'struct', 'textwrap', 'types', 'warnings', 'weakref'] Patched: $ ./python -c 'import sys; s = set(sys.modules); import argparse; print(len(s), len(sys.modules), len(set(sys.modules) - s)); print(sorted(set(sys.modules) - s))' 35 55 20 ['_collections', '_functools', '_locale', '_operator', '_sre', 'argparse', 'collections', 'copyreg', 'enum', 'functools', 'itertools', 'keyword', 'operator', 're', 'reprlib', 'sre_compile', 'sre_constants', 'sre_parse', 'types', 'weakref'] $ ./python -S -c 'import sys; s = set(sys.modules); import argparse; print(len(s), len(sys.modules), len(set(sys.modules) - s)); print(sorted(set(sys.modules) - s))' 23 51 28 ['_collections', '_collections_abc', '_functools', '_locale', '_operator', '_sre', '_stat', 'argparse', 'collections', 'copyreg', 'enum', 'errno', 'functools', 'genericpath', 'itertools', 'keyword', 'operator', 'os', 'os.path', 'posixpath', 're', 'reprlib', 'sre_compile', 'sre_constants', 'sre_parse', 'stat', 'types', 'weakref'] The patch defers importing rarely used modules. For example textwrap and gettext are used only for output a help and error messages. The patch also makes argparse itself be imported only when the module is used as a script, not just imported. The patch also replaces importing collections.abc with _collections_abc in some other basic modules (like pathlib), this could allow to avoid importing the collections package if it is not used. Unavoided imports: * functools is used in re for decorating _compile_repl with lru_cache. * collections is used in functools for making CacheInfo a named tuple. * enum is used in re for creating RegexFlag. * types is used in enum for decorating some properties with DynamicClassAttribute. ---------- components: Library (Lib) messages: 292200 nosy: bethard, haypo, rhettinger, serhiy.storchaka priority: normal severity: normal stage: patch review status: open title: Reduce the number of imports for argparse type: enhancement versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue30152> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
