Enforce word boundaries in operators and names

This ensures that these are only parsed when they're independent words.

packaging/_tokenizer.py

@@ -53,12 +53,12 @@ def __str__(self) -> str:
  re.VERBOSE,
  ),
  "OP": r"(===|==|~=|!=|<=|>=|<|>)",
- "BOOLOP": r"(or|and)",
- "IN": r"in",
- "NOT": r"not",
+ "BOOLOP": r"\b(or|and)\b",
+ "IN": r"\bin\b",
+ "NOT": r"\bnot\b",
  "VARIABLE": re.compile(
  r"""
- (
+ \b(
  python_version
  |python_full_version
  |os[._]name
@@ -68,14 +68,14 @@ def __str__(self) -> str:
  |python_implementation
  |implementation_(name|version)
  |extra
- )
+ )\b
  """,
  re.VERBOSE,
  ),
  "VERSION": re.compile(Specifier._version_regex_str, re.VERBOSE | re.IGNORECASE),
  "AT": r"\@",
  "URL": r"[^ \t]+",
- "IDENTIFIER": r"[a-zA-Z0-9][a-zA-Z0-9._-]*",
+ "IDENTIFIER": r"\b[a-zA-Z0-9][a-zA-Z0-9._-]*\b",
  "WS": r"[ \t]+",
  "END": r"$",
 }

tests/test_requirements.py

@@ -390,9 +390,27 @@ def test_error_invalid_marker_notin_without_whitespace(self) -> None:
  # THEN
  assert ctx.exconly() == (
  "packaging.requirements.InvalidRequirement: "
- "Expected whitespace after 'not'\n"
+ "Expected marker operator, one of <=, <, !=, ==, >=, >, ~=, ===, "
+ "not, not in\n"
  " name; '3.7' notin python_version\n"
- " ^"
+ " ^"
+ )
+
+ def test_error_when_no_word_boundary(self) -> None:
+ # GIVEN
+ to_parse = "name; '3.6'inpython_version"
+
+ # WHEN
+ with pytest.raises(InvalidRequirement) as ctx:
+ Requirement(to_parse)
+
+ # THEN
+ assert ctx.exconly() == (
+ "packaging.requirements.InvalidRequirement: "
+ "Expected marker operator, one of <=, <, !=, ==, >=, >, ~=, ===, "
+ "not, not in\n"
+ " name; '3.6'inpython_version\n"
+ " ^"
  )
 
  def test_error_invalid_marker_not_without_in(self) -> None: