Note that this doesn't actually encompass all the possible usages of the PEP-572 operator in the standard library, of which there appear to be 312 more candidat

Note that this doesn't actually encompass all the possible usages of the PEP-572 operator in the standard library, of which there appear to be 312 more candidates (and a further 100 in the rest of CPython): root@8d88e1e678b0:/cpython# astpath -A 1 "//Assign[(targets/Name/@id = following-sibling::*[1][name(.) = 'If']/test/Name/@id)]" > pep-572.txt root@8d88e1e678b0:/cpython# grep "Lib" pep-572.txt | head -20 ./Lib/argparse.py:284 > help = self._root_section.format_help() ./Lib/argparse.py:285 if help: ./Lib/argparse.py:2275 > a = [action for action in positionals ./Lib/argparse.py:2276 if action.nargs in [PARSER, REMAINDER]] ./Lib/cmd.py:300 > doc=getattr(self, 'do_' + arg).__doc__ ./Lib/cmd.py:301 if doc: ./Lib/cmd.py:356 > nonstrings = [i for i in range(len(list)) ./Lib/cmd.py:357 if not isinstance(list[i], str)] ./Lib/compileall.py:123 > mo = rx.search(fullname) ./Lib/compileall.py:124 if mo: ./Lib/dis.py:386 > show_lineno = linestarts is not None ./Lib/dis.py:387 if show_lineno: ./Lib/dis.py:403 > new_source_line = (show_lineno and ./Lib/dis.py:404 instr.starts_line is not None and ./Lib/enum.py:86 > already = set(value) & set(self._member_names) ./Lib/enum.py:87 if already: ./Lib/enum.py:153 > invalid_names = set(enum_members) & {'mro', } ./Lib/enum.py:154 if invalid_names: ./Lib/enum.py:848 > negative = value < 0 ./Lib/enum.py:849 # issue29167: wrap accesses to _value2member_map_ in a list to avoid race root@8d88e1e678b0:/cpython# grep -E "\.py\:[^w]+>" pep-572.txt | wc -l 412 root@8d88e1e678b0:/cpython# grep -E "/Lib/.+\.py\:[^w]+>" pep-572.txt | wc -l 312