gh-155358: [WIP] Deprecate tuple API of structseq objects

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I created this draft PR to check if it's possible to implement the deprecation of the tuple API of structseq types, and check how much stdlib code would be impacted by these deprecations.

• Issue: Deprecate the tuple API (object[index]) of structseq types (ex: os.stat_result) #155358

[vstinner]

pip and setuptools fail with these changes. The issue can be seen in test_cext and test_cppext for example.

pip:

 File "pip/_internal/cli/parser.py", line 45, in __init__
kwargs["width"] = shutil.get_terminal_size()[0] - 2

setuptools:

 File "setuptools/_distutils/file_util.py", line 164, in copy_file
os.utime(dst, (st[ST_ATIME], st[ST_MTIME]))

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Notes to replace tuple API with named attributes.

os.stat():

• st[0] => st.st_mode
• st[1] => st.st_ino
• st[2] => st.st_dev
• st[3] => st.st_nlink
• st[4] => st.st_uid
• st[5] => st.st_gid
• st[6] => st.st_size
• st[7] => st.st_atime (int => float)
• st[8] => st.st_mtime (int => `float)
• st[9] => st.st_ctime (int => float)

pwd:

• e[0] => e.pw_name
• e[1] => e.pw_passwd
• e[2] => e.pw_uid
• e[3] => e.pw_gid
• e[4] => e.pw_gecos
• e[5] => e.pw_dir
• e[6] => e.pw_shell

grp:

• e[0] => e.gr_name
• e[1] => e.gr_passwd
• e[2] => e.gr_gid
• e[3] => e.gr_mem

pkgutil.ModuleInfo:

• e[0] => e.module_finder
• e[1] => e.name
• e[2] => e.ispkg

urllib.parse.urlsplit():

• res[0] => res.scheme
• res[1] => res.netloc
• res[2] => res.path
• res[3] => res.query
• res[4] => res.fragment

urllib.parse.urlparse():

• res[0] => res.scheme
• res[1] => res.netloc
• res[2] => res.path
• res[3] => res.params
• res[4] => res.query
• res[5] => res.fragment

test.support.script_helper:

• proc[0] => proc.rc
• proc[1] => proc.out
• proc[2] => proc.err

os.statvfs:

• st[0] => st.f_bsize
• st[1] => st.f_frsize
• st[2] => st.f_blocks
• st[3] => st.f_bfree
• st[4] => st.f_bavail
• st[5] => st.f_files
• st[6] => st.f_ffree
• st[7] => st.f_favail
• st[8] => st.f_flag
• st[9] => st.f_namemax
• st[10] => st.f_fsid

inspect.stack() items:

• f[0] => f.frame
• f[1] => f.filename
• f[2] => f.lineno
• f[3] => f.function
• f[4] => f.code_context

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Oh, the setuptools issue has already been fixed in setuptools 84.0.0 with commit pypa/setuptools@39a64a0. Right now, CPython embeds setuptools 79 in Lib/test/wheeldata/setuptools-79.0.1-py3-none-any.whl.