Remove Python 2 support (#2740)

*blib2to3's support was left untouched because: 1) I don't want to touch
parsing machinery, and 2) it'll allow us to provide a more useful error
message if someone does try to format Python 2 code.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -16,7 +16,7 @@ current development version. To confirm this, you have three options:
 3. Or run _Black_ on your machine:
    - create a new virtualenv (make sure it's the same Python version);
    - clone this repository;
-   - run `pip install -e .[d,python2]`;
+   - run `pip install -e .[d]`;
    - run `pip install -r test_requirements.txt`
    - make sure it's sane by running `python -m pytest`; and
    - run `black` like you did last time.

CHANGES.md

@@ -4,6 +4,7 @@
 
 ### _Black_
 
+- **Remove Python 2 support** (#2740)
 - Do not accept bare carriage return line endings in pyproject.toml (#2408)
 - Improve error message for invalid regular expression (#2678)
 - Improve error message when parsing fails during AST safety check by embedding the

README.md

@@ -40,9 +40,7 @@ Try it out now using the [Black Playground](https://black.vercel.app). Watch the
 ### Installation
 
 _Black_ can be installed by running `pip install black`. It requires Python 3.6.2+ to
-run. If you want to format Python 2 code as well, install with
+run. If you want to format Jupyter Notebooks, install with `pip install black[jupyter]`.
-`pip install black[python2]`. If you want to format Jupyter Notebooks, install with
-`pip install black[jupyter]`.
 
 If you can't wait for the latest _hotness_ and want to install from GitHub, use:
 

action/main.py

@@ -14,7 +14,7 @@
 
 run([sys.executable, "-m", "venv", str(ENV_PATH)], check=True)
 
-req = "black[colorama,python2]"
+req = "black[colorama]"
 if VERSION:
     req += f"=={VERSION}"
 pip_proc = run(

docs/faq.md

@@ -75,16 +75,7 @@ disabled-by-default counterpart W504. E203 should be disabled while changes are
 
 ## Does Black support Python 2?
 
-```{warning}
+Support for formatting Python 2 code was removed in version 22.0.
-Python 2 support has been deprecated since 21.10b0.
-
-This support will be dropped in the first stable release, expected for January 2022.
-See [The Black Code Style](the_black_code_style/index.rst) for details.
-```
-
-For formatting, yes! [Install](getting_started.md#installation) with the `python2` extra
-to format Python 2 files too! In terms of running _Black_ though, Python 3.6 or newer is
-required.
 
 ## Why does my linter or typechecker complain after I format my code?
 
@@ -96,8 +87,7 @@ codebase with _Black_.
 
 ## Can I run Black with PyPy?
 
-Yes, there is support for PyPy 3.7 and higher. You cannot format Python 2 files under
+Yes, there is support for PyPy 3.7 and higher.
-PyPy, because PyPy's inbuilt ast module does not support this.
 
 ## Why does Black not detect syntax errors in my code?
 

docs/getting_started.md

@@ -17,9 +17,7 @@ Also, you can try out _Black_ online for minimal fuss on the
 ## Installation
 
 _Black_ can be installed by running `pip install black`. It requires Python 3.6.2+ to
-run, but can format Python 2 code too. Python 2 support needs the `typed_ast`
+run. If you want to format Jupyter Notebooks, install with `pip install black[jupyter]`.
-dependency, which be installed with `pip install black[python2]`. If you want to format
-Jupyter Notebooks, install with `pip install black[jupyter]`.
 
 If you can't wait for the latest _hotness_ and want to install from GitHub, use:
 

docs/integrations/github_actions.md

@@ -8,8 +8,8 @@ environment. Great for enforcing that your code matches the _Black_ code style.
 This action is known to support all GitHub-hosted runner OSes. In addition, only
 published versions of _Black_ are supported (i.e. whatever is available on PyPI).
 
-Finally, this action installs _Black_ with both the `colorama` and `python2` extras so
+Finally, this action installs _Black_ with the `colorama` extra so the `--color` flag
-the `--color` flag and formatting Python 2 code are supported.
+should work fine.
 
 ## Usage
 

docs/the_black_code_style/current_style.md

@@ -281,8 +281,7 @@ removed.
 
 _Black_ standardizes most numeric literals to use lowercase letters for the syntactic
 parts and uppercase letters for the digits themselves: `0xAB` instead of `0XAB` and
-`1e10` instead of `1E10`. Python 2 long literals are styled as `2L` instead of `2l` to
+`1e10` instead of `1E10`.
-avoid confusion between `l` and `1`.
 
 ### Line breaks & binary operators
 

pyproject.toml

@@ -29,7 +29,6 @@ build-backend = "setuptools.build_meta"
 [tool.pytest.ini_options]
 # Option below requires `tests/optional.py`
 optional-tests = [
-  "no_python2: run when `python2` extra NOT installed",
   "no_blackd: run when `d` extra NOT installed",
   "no_jupyter: run when `jupyter` extra NOT installed",
 ]

setup.py

@@ -112,7 +112,6 @@ def find_python_files(base: Path) -> List[Path]:
     extras_require={
         "d": ["aiohttp>=3.7.4"],
         "colorama": ["colorama>=0.4.3"],
-        "python2": ["typed-ast>=1.4.3"],
         "uvloop": ["uvloop>=0.15.2"],
         "jupyter": ["ipython>=7.8.0", "tokenize-rt>=3.2.0"],
     },

src/black/__init__.py

@@ -1083,20 +1083,8 @@ def f(
     else:
         versions = detect_target_versions(src_node, future_imports=future_imports)
 
-    # TODO: fully drop support and this code hopefully in January 2022 :D
-    if TargetVersion.PY27 in mode.target_versions or versions == {TargetVersion.PY27}:
-        msg = (
-            "DEPRECATION: Python 2 support will be removed in the first stable release "
-            "expected in January 2022."
-        )
-        err(msg, fg="yellow", bold=True)
-
     normalize_fmt_off(src_node)
-    lines = LineGenerator(
+    lines = LineGenerator(mode=mode)
-        mode=mode,
-        remove_u_prefix="unicode_literals" in future_imports
-        or supports_feature(versions, Feature.UNICODE_LITERALS),
-    )
     elt = EmptyLineTracker(is_pyi=mode.is_pyi)
     empty_line = Line(mode=mode)
     after = 0
@@ -1166,14 +1154,6 @@ def get_features_used(  # noqa: C901
             assert isinstance(n, Leaf)
             if "_" in n.value:
                 features.add(Feature.NUMERIC_UNDERSCORES)
-            elif n.value.endswith(("L", "l")):
-                # Python 2: 10L
-                features.add(Feature.LONG_INT_LITERAL)
-            elif len(n.value) >= 2 and n.value[0] == "0" and n.value[1].isdigit():
-                # Python 2: 0123; 00123; ...
-                if not all(char == "0" for char in n.value):
-                    # although we don't want to match 0000 or similar
-                    features.add(Feature.OCTAL_INT_LITERAL)
 
         elif n.type == token.SLASH:
             if n.parent and n.parent.type in {
@@ -1226,32 +1206,6 @@ def get_features_used(  # noqa: C901
         ):
             features.add(Feature.ANN_ASSIGN_EXTENDED_RHS)
 
-        # Python 2 only features (for its deprecation) except for integers, see above
-        elif n.type == syms.print_stmt:
-            features.add(Feature.PRINT_STMT)
-        elif n.type == syms.exec_stmt:
-            features.add(Feature.EXEC_STMT)
-        elif n.type == syms.tfpdef:
-            # def set_position((x, y), value):
-            #     ...
-            features.add(Feature.AUTOMATIC_PARAMETER_UNPACKING)
-        elif n.type == syms.except_clause:
-            # try:
-            #     ...
-            # except Exception, err:
-            #     ...
-            if len(n.children) >= 4:
-                if n.children[-2].type == token.COMMA:
-                    features.add(Feature.COMMA_STYLE_EXCEPT)
-        elif n.type == syms.raise_stmt:
-            # raise Exception, "msg"
-            if len(n.children) >= 4:
-                if n.children[-2].type == token.COMMA:
-                    features.add(Feature.COMMA_STYLE_RAISE)
-        elif n.type == token.BACKQUOTE:
-            # `i'm surprised this ever existed`
-            features.add(Feature.BACKQUOTE_REPR)
-
     return features
 
 

src/black/linegen.py

@@ -48,9 +48,8 @@ class LineGenerator(Visitor[Line]):
     in ways that will no longer stringify to valid Python code on the tree.
     """
 
-    def __init__(self, mode: Mode, remove_u_prefix: bool = False) -> None:
+    def __init__(self, mode: Mode) -> None:
         self.mode = mode
-        self.remove_u_prefix = remove_u_prefix
         self.current_line: Line
         self.__post_init__()
 
@@ -92,9 +91,7 @@ def visit_default(self, node: LN) -> Iterator[Line]:
 
             normalize_prefix(node, inside_brackets=any_open_brackets)
             if self.mode.string_normalization and node.type == token.STRING:
-                node.value = normalize_string_prefix(
+                node.value = normalize_string_prefix(node.value)
-                    node.value, remove_u_prefix=self.remove_u_prefix
-                )
                 node.value = normalize_string_quotes(node.value)
             if node.type == token.NUMBER:
                 normalize_numeric_literal(node)
@@ -236,7 +233,7 @@ def visit_STRING(self, leaf: Leaf) -> Iterator[Line]:
         if is_docstring(leaf) and "\\\n" not in leaf.value:
             # We're ignoring docstrings with backslash newline escapes because changing
             # indentation of those changes the AST representation of the code.
-            docstring = normalize_string_prefix(leaf.value, self.remove_u_prefix)
+            docstring = normalize_string_prefix(leaf.value)
             prefix = get_string_prefix(docstring)
             docstring = docstring[len(prefix) :]  # Remove the prefix
             quote_char = docstring[0]

src/black/mode.py

@@ -20,7 +20,6 @@
 
 
 class TargetVersion(Enum):
-    PY27 = 2
     PY33 = 3
     PY34 = 4
     PY35 = 5
@@ -30,13 +29,8 @@ class TargetVersion(Enum):
     PY39 = 9
     PY310 = 10
 
-    def is_python2(self) -> bool:
-        return self is TargetVersion.PY27
-
 
 class Feature(Enum):
-    # All string literals are unicode
-    UNICODE_LITERALS = 1
     F_STRINGS = 2
     NUMERIC_UNDERSCORES = 3
     TRAILING_COMMA_IN_CALL = 4
@@ -56,16 +50,6 @@ class Feature(Enum):
     # __future__ flags
     FUTURE_ANNOTATIONS = 51
 
-    # temporary for Python 2 deprecation
-    PRINT_STMT = 200
-    EXEC_STMT = 201
-    AUTOMATIC_PARAMETER_UNPACKING = 202
-    COMMA_STYLE_EXCEPT = 203
-    COMMA_STYLE_RAISE = 204
-    LONG_INT_LITERAL = 205
-    OCTAL_INT_LITERAL = 206
-    BACKQUOTE_REPR = 207
-
 
 FUTURE_FLAG_TO_FEATURE: Final = {
     "annotations": Feature.FUTURE_ANNOTATIONS,
@@ -73,26 +57,10 @@ class Feature(Enum):
 
 
 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
-    TargetVersion.PY27: {
+    TargetVersion.PY33: {Feature.ASYNC_IDENTIFIERS},
-        Feature.ASYNC_IDENTIFIERS,
+    TargetVersion.PY34: {Feature.ASYNC_IDENTIFIERS},
-        Feature.PRINT_STMT,
+    TargetVersion.PY35: {Feature.TRAILING_COMMA_IN_CALL, Feature.ASYNC_IDENTIFIERS},
-        Feature.EXEC_STMT,
-        Feature.AUTOMATIC_PARAMETER_UNPACKING,
-        Feature.COMMA_STYLE_EXCEPT,
-        Feature.COMMA_STYLE_RAISE,
-        Feature.LONG_INT_LITERAL,
-        Feature.OCTAL_INT_LITERAL,
-        Feature.BACKQUOTE_REPR,
-    },
-    TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
-    TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
-    TargetVersion.PY35: {
-        Feature.UNICODE_LITERALS,
-        Feature.TRAILING_COMMA_IN_CALL,
-        Feature.ASYNC_IDENTIFIERS,
-    },
     TargetVersion.PY36: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
@@ -100,7 +68,6 @@ class Feature(Enum):
         Feature.ASYNC_IDENTIFIERS,
     },
     TargetVersion.PY37: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
@@ -109,7 +76,6 @@ class Feature(Enum):
         Feature.FUTURE_ANNOTATIONS,
     },
     TargetVersion.PY38: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
@@ -122,7 +88,6 @@ class Feature(Enum):
         Feature.ANN_ASSIGN_EXTENDED_RHS,
     },
     TargetVersion.PY39: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
@@ -136,7 +101,6 @@ class Feature(Enum):
         Feature.ANN_ASSIGN_EXTENDED_RHS,
     },
     TargetVersion.PY310: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,

src/black/nodes.py

@@ -259,16 +259,6 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
         ):
             return NO
 
-        elif (
-            prevp.type == token.RIGHTSHIFT
-            and prevp.parent
-            and prevp.parent.type == syms.shift_expr
-            and prevp.prev_sibling
-            and is_name_token(prevp.prev_sibling)
-            and prevp.prev_sibling.value == "print"
-        ):
-            # Python 2 print chevron
-            return NO
         elif prevp.type == token.AT and p.parent and p.parent.type == syms.decorator:
             # no space in decorators
             return NO

src/black/numerics.py

@@ -25,13 +25,10 @@ def format_scientific_notation(text: str) -> str:
     return f"{before}e{sign}{after}"
 
 
-def format_long_or_complex_number(text: str) -> str:
+def format_complex_number(text: str) -> str:
-    """Formats a long or complex string like `10L` or `10j`"""
+    """Formats a complex string like `10j`"""
     number = text[:-1]
     suffix = text[-1]
-    # Capitalize in "2L" because "l" looks too similar to "1".
-    if suffix == "l":
-        suffix = "L"
     return f"{format_float_or_int_string(number)}{suffix}"
 
 
@@ -47,9 +44,7 @@ def format_float_or_int_string(text: str) -> str:
 def normalize_numeric_literal(leaf: Leaf) -> None:
     """Normalizes numeric (float, int, and complex) literals.
 
-    All letters used in the representation are normalized to lowercase (except
+    All letters used in the representation are normalized to lowercase."""
-    in Python 2 long literals).
-    """
     text = leaf.value.lower()
     if text.startswith(("0o", "0b")):
         # Leave octal and binary literals alone.
@@ -58,8 +53,8 @@ def normalize_numeric_literal(leaf: Leaf) -> None:
         text = format_hex(text)
     elif "e" in text:
         text = format_scientific_notation(text)
-    elif text.endswith(("j", "l")):
+    elif text.endswith("j"):
-        text = format_long_or_complex_number(text)
+        text = format_complex_number(text)
     else:
         text = format_float_or_int_string(text)
     leaf.value = text

src/black/parsing.py

@@ -4,7 +4,7 @@
 import ast
 import platform
 import sys
-from typing import Any, AnyStr, Iterable, Iterator, List, Set, Tuple, Type, Union
+from typing import Any, Iterable, Iterator, List, Set, Tuple, Type, Union
 
 if sys.version_info < (3, 8):
     from typing_extensions import Final
@@ -23,12 +23,11 @@
 from black.nodes import syms
 
 ast3: Any
-ast27: Any
 
 _IS_PYPY = platform.python_implementation() == "PyPy"
 
 try:
-    from typed_ast import ast3, ast27
+    from typed_ast import ast3
 except ImportError:
     # Either our python version is too low, or we're on pypy
     if sys.version_info < (3, 7) or (sys.version_info < (3, 8) and not _IS_PYPY):
@@ -40,12 +39,11 @@
         )
         sys.exit(1)
     else:
-        ast3 = ast27 = ast
+        ast3 = ast
 
 
-PY310_HINT: Final[
+PY310_HINT: Final = "Consider using --target-version py310 to parse Python 3.10 code."
-    str
+PY2_HINT: Final = "Python 2 support was removed in version 22.0."
-] = "Consider using --target-version py310 to parse Python 3.10 code."
 
 
 class InvalidInput(ValueError):
@@ -60,22 +58,8 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
             pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
             # Python 3.0-3.6
             pygram.python_grammar_no_print_statement_no_exec_statement,
-            # Python 2.7 with future print_function import
-            pygram.python_grammar_no_print_statement,
-            # Python 2.7
-            pygram.python_grammar,
         ]
 
-    if all(version.is_python2() for version in target_versions):
-        # Python 2-only code, so try Python 2 grammars.
-        return [
-            # Python 2.7 with future print_function import
-            pygram.python_grammar_no_print_statement,
-            # Python 2.7
-            pygram.python_grammar,
-        ]
-
-    # Python 3-compatible code, so only try Python 3 grammar.
     grammars = []
     if supports_feature(target_versions, Feature.PATTERN_MATCHING):
         # Python 3.10+
@@ -129,6 +113,14 @@ def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -
             original_msg = exc.args[0]
             msg = f"{original_msg}\n{PY310_HINT}"
             raise InvalidInput(msg) from None
+
+        if matches_grammar(src_txt, pygram.python_grammar) or matches_grammar(
+            src_txt, pygram.python_grammar_no_print_statement
+        ):
+            original_msg = exc.args[0]
+            msg = f"{original_msg}\n{PY2_HINT}"
+            raise InvalidInput(msg) from None
+
         raise exc from None
 
     if isinstance(result, Leaf):
@@ -154,7 +146,7 @@ def lib2to3_unparse(node: Node) -> str:
 
 def parse_single_version(
     src: str, version: Tuple[int, int]
-) -> Union[ast.AST, ast3.AST, ast27.AST]:
+) -> Union[ast.AST, ast3.AST]:
     filename = "<unknown>"
     # typed_ast is needed because of feature version limitations in the builtin ast
     if sys.version_info >= (3, 8) and version >= (3,):
@@ -164,18 +156,13 @@ def parse_single_version(
             return ast3.parse(src, filename)
         else:
             return ast3.parse(src, filename, feature_version=version[1])
-    elif version == (2, 7):
-        return ast27.parse(src)
     raise AssertionError("INTERNAL ERROR: Tried parsing unsupported Python version!")
 
 
-def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]:
+def parse_ast(src: str) -> Union[ast.AST, ast3.AST]:
     # TODO: support Python 4+ ;)
     versions = [(3, minor) for minor in range(3, sys.version_info[1] + 1)]
 
-    if ast27.__name__ != "ast":
-        versions.append((2, 7))
-
     first_error = ""
     for version in sorted(versions, reverse=True):
         try:
@@ -188,22 +175,19 @@ def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]:
 
 
 ast3_AST: Final[Type[ast3.AST]] = ast3.AST
-ast27_AST: Final[Type[ast27.AST]] = ast27.AST
 
 
-def _normalize(lineend: AnyStr, value: AnyStr) -> AnyStr:
+def _normalize(lineend: str, value: str) -> str:
     # To normalize, we strip any leading and trailing space from
     # each line...
-    stripped: List[AnyStr] = [i.strip() for i in value.splitlines()]
+    stripped: List[str] = [i.strip() for i in value.splitlines()]
     normalized = lineend.join(stripped)
     # ...and remove any blank lines at the beginning and end of
     # the whole string
     return normalized.strip()
 
 
-def stringify_ast(
+def stringify_ast(node: Union[ast.AST, ast3.AST], depth: int = 0) -> Iterator[str]:
-    node: Union[ast.AST, ast3.AST, ast27.AST], depth: int = 0
-) -> Iterator[str]:
     """Simple visitor generating strings to compare ASTs by content."""
 
     node = fixup_ast_constants(node)
@@ -215,7 +199,7 @@ def stringify_ast(
         # TypeIgnore will not be present using pypy < 3.8, so need for this
         if not (_IS_PYPY and sys.version_info < (3, 8)):
             # TypeIgnore has only one field 'lineno' which breaks this comparison
-            type_ignore_classes = (ast3.TypeIgnore, ast27.TypeIgnore)
+            type_ignore_classes = (ast3.TypeIgnore,)
             if sys.version_info >= (3, 8):
                 type_ignore_classes += (ast.TypeIgnore,)
             if isinstance(node, type_ignore_classes):
@@ -234,40 +218,34 @@ def stringify_ast(
                 # parentheses and they change the AST.
                 if (
                     field == "targets"
-                    and isinstance(node, (ast.Delete, ast3.Delete, ast27.Delete))
+                    and isinstance(node, (ast.Delete, ast3.Delete))
-                    and isinstance(item, (ast.Tuple, ast3.Tuple, ast27.Tuple))
+                    and isinstance(item, (ast.Tuple, ast3.Tuple))
                 ):
                     for item in item.elts:
                         yield from stringify_ast(item, depth + 2)
 
-                elif isinstance(item, (ast.AST, ast3.AST, ast27.AST)):
+                elif isinstance(item, (ast.AST, ast3.AST)):
                     yield from stringify_ast(item, depth + 2)
 
         # Note that we are referencing the typed-ast ASTs via global variables and not
         # direct module attribute accesses because that breaks mypyc. It's probably
-        # something to do with the ast3 / ast27 variables being marked as Any leading
+        # something to do with the ast3 variables being marked as Any leading
         # mypy to think this branch is always taken, leaving the rest of the code
         # unanalyzed. Tighting up the types for the typed-ast AST types avoids the
         # mypyc crash.
-        elif isinstance(value, (ast.AST, ast3_AST, ast27_AST)):
+        elif isinstance(value, (ast.AST, ast3_AST)):
             yield from stringify_ast(value, depth + 2)
 
         else:
             # Constant strings may be indented across newlines, if they are
             # docstrings; fold spaces after newlines when comparing. Similarly,
             # trailing and leading space may be removed.
-            # Note that when formatting Python 2 code, at least with Windows
-            # line-endings, docstrings can end up here as bytes instead of
-            # str so make sure that we handle both cases.
             if (
                 isinstance(node, ast.Constant)
                 and field == "value"
-                and isinstance(value, (str, bytes))
+                and isinstance(value, str)
             ):
-                if isinstance(value, str):
+                normalized = _normalize("\n", value)
-                    normalized: Union[str, bytes] = _normalize("\n", value)
-                else:
-                    normalized = _normalize(b"\n", value)
             else:
                 normalized = value
             yield f"{'  ' * (depth+2)}{normalized!r},  # {value.__class__.__name__}"
@@ -275,14 +253,12 @@ def stringify_ast(
     yield f"{'  ' * depth})  # /{node.__class__.__name__}"
 
 
-def fixup_ast_constants(
+def fixup_ast_constants(node: Union[ast.AST, ast3.AST]) -> Union[ast.AST, ast3.AST]:
-    node: Union[ast.AST, ast3.AST, ast27.AST]
-) -> Union[ast.AST, ast3.AST, ast27.AST]:
     """Map ast nodes deprecated in 3.8 to Constant."""
-    if isinstance(node, (ast.Str, ast3.Str, ast27.Str, ast.Bytes, ast3.Bytes)):
+    if isinstance(node, (ast.Str, ast3.Str, ast.Bytes, ast3.Bytes)):
         return ast.Constant(value=node.s)
 
-    if isinstance(node, (ast.Num, ast3.Num, ast27.Num)):
+    if isinstance(node, (ast.Num, ast3.Num)):
         return ast.Constant(value=node.n)
 
     if isinstance(node, (ast.NameConstant, ast3.NameConstant)):

src/black/strings.py

@@ -138,17 +138,17 @@ def assert_is_leaf_string(string: str) -> None:
     ), f"{set(string[:quote_idx])} is NOT a subset of {set(STRING_PREFIX_CHARS)}."
 
 
-def normalize_string_prefix(s: str, remove_u_prefix: bool = False) -> str:
+def normalize_string_prefix(s: str) -> str:
-    """Make all string prefixes lowercase.
+    """Make all string prefixes lowercase."""
-
-    If remove_u_prefix is given, also removes any u prefix from the string.
-    """
     match = STRING_PREFIX_RE.match(s)
     assert match is not None, f"failed to match string {s!r}"
     orig_prefix = match.group(1)
-    new_prefix = orig_prefix.replace("F", "f").replace("B", "b").replace("U", "u")
+    new_prefix = (
-    if remove_u_prefix:
+        orig_prefix.replace("F", "f")
-        new_prefix = new_prefix.replace("u", "")
+        .replace("B", "b")
+        .replace("U", "")
+        .replace("u", "")
+    )
     return f"{new_prefix}{match.group(2)}"
 
 

src/black_primer/primer.json

@@ -149,17 +149,6 @@
       "long_checkout": false,
       "py_versions": ["all"]
     },
-    "sqlalchemy": {
-      "cli_arguments": [
-        "--experimental-string-processing",
-        "--extend-exclude",
-        "/test/orm/test_relationship_criteria.py"
-      ],
-      "expect_formatting_changes": true,
-      "git_clone_url": "https://github.com/sqlalchemy/sqlalchemy.git",
-      "long_checkout": false,
-      "py_versions": ["all"]
-    },
     "tox": {
       "cli_arguments": ["--experimental-string-processing"],
       "expect_formatting_changes": true,

src/blackd/__init__.py

@@ -174,10 +174,8 @@ def parse_python_variant_header(value: str) -> Tuple[bool, Set[black.TargetVersi
                     raise InvalidVariantHeader("major version must be 2 or 3")
                 if len(rest) > 0:
                     minor = int(rest[0])
-                    if major == 2 and minor != 7:
+                    if major == 2:
-                        raise InvalidVariantHeader(
+                        raise InvalidVariantHeader("Python 2 is not supported")
-                            "minor version must be 7 for Python 2"
-                        )
                 else:
                     # Default to lowest supported minor version.
                     minor = 7 if major == 2 else 3

tests/data/numeric_literals_py2.py

@@ -1,16 +0,0 @@
-#!/usr/bin/env python2.7
-
-x = 123456789L
-x = 123456789l
-x = 123456789
-x = 0xb1acc
-
-# output
-
-
-#!/usr/bin/env python2.7
-
-x = 123456789L
-x = 123456789L
-x = 123456789
-x = 0xB1ACC

tests/data/python2.py

@@ -1,33 +0,0 @@
-#!/usr/bin/env python2
-
-import sys
-
-print >> sys.stderr , "Warning:" ,
-print >> sys.stderr , "this is a blast from the past."
-print >> sys.stderr , "Look, a repr:", `sys`
-
-
-def function((_globals, _locals)):
-    exec ur"print 'hi from exec!'" in _globals, _locals
-
-
-function((globals(), locals()))
-
-
-# output
-
-
-#!/usr/bin/env python2
-
-import sys
-
-print >>sys.stderr, "Warning:",
-print >>sys.stderr, "this is a blast from the past."
-print >>sys.stderr, "Look, a repr:", ` sys `
-
-
-def function((_globals, _locals)):
-    exec ur"print 'hi from exec!'" in _globals, _locals
-
-
-function((globals(), locals()))

tests/data/python2_print_function.py

@@ -1,16 +0,0 @@
-#!/usr/bin/env python2
-from __future__ import print_function
-
-print('hello')
-print(u'hello')
-print(a, file=sys.stderr)
-
-# output
-
-
-#!/usr/bin/env python2
-from __future__ import print_function
-
-print("hello")
-print(u"hello")
-print(a, file=sys.stderr)

tests/data/python2_unicode_literals.py

@@ -1,20 +0,0 @@
-#!/usr/bin/env python2
-from __future__ import unicode_literals as _unicode_literals
-from __future__ import absolute_import
-from __future__ import print_function as lol, with_function
-
-u'hello'
-U"hello"
-Ur"hello"
-
-# output
-
-
-#!/usr/bin/env python2
-from __future__ import unicode_literals as _unicode_literals
-from __future__ import absolute_import
-from __future__ import print_function as lol, with_function
-
-"hello"
-"hello"
-r"hello"

tests/test_black.py

@@ -724,24 +724,15 @@ def test_lib2to3_parse(self) -> None:
 
         straddling = "x + y"
         black.lib2to3_parse(straddling)
-        black.lib2to3_parse(straddling, {TargetVersion.PY27})
         black.lib2to3_parse(straddling, {TargetVersion.PY36})
-        black.lib2to3_parse(straddling, {TargetVersion.PY27, TargetVersion.PY36})
 
         py2_only = "print x"
-        black.lib2to3_parse(py2_only)
-        black.lib2to3_parse(py2_only, {TargetVersion.PY27})
         with self.assertRaises(black.InvalidInput):
             black.lib2to3_parse(py2_only, {TargetVersion.PY36})
-        with self.assertRaises(black.InvalidInput):
-            black.lib2to3_parse(py2_only, {TargetVersion.PY27, TargetVersion.PY36})
 
         py3_only = "exec(x, end=y)"
         black.lib2to3_parse(py3_only)
-        with self.assertRaises(black.InvalidInput):
-            black.lib2to3_parse(py3_only, {TargetVersion.PY27})
         black.lib2to3_parse(py3_only, {TargetVersion.PY36})
-        black.lib2to3_parse(py3_only, {TargetVersion.PY27, TargetVersion.PY36})
 
     def test_get_features_used_decorator(self) -> None:
         # Test the feature detection of new decorator syntax
@@ -1436,27 +1427,6 @@ def test_bpo_2142_workaround(self) -> None:
         actual = diff_header.sub(DETERMINISTIC_HEADER, actual)
         self.assertEqual(actual, expected)
 
-    @pytest.mark.python2
-    def test_docstring_reformat_for_py27(self) -> None:
-        """
-        Check that stripping trailing whitespace from Python 2 docstrings
-        doesn't trigger a "not equivalent to source" error
-        """
-        source = (
-            b'def foo():\r\n    """Testing\r\n    Testing """\r\n    print "Foo"\r\n'
-        )
-        expected = 'def foo():\n    """Testing\n    Testing"""\n    print "Foo"\n'
-
-        result = BlackRunner().invoke(
-            black.main,
-            ["-", "-q", "--target-version=py27"],
-            input=BytesIO(source),
-        )
-
-        self.assertEqual(result.exit_code, 0)
-        actual = result.stdout
-        self.assertFormatEqual(actual, expected)
-
     @staticmethod
     def compare_results(
         result: click.testing.Result, expected_value: str, expected_exit_code: int
@@ -2086,36 +2056,6 @@ def test_get_sources_with_stdin_filename_and_force_exclude(self) -> None:
         )
 
 
-@pytest.mark.python2
-@pytest.mark.parametrize("explicit", [True, False], ids=["explicit", "autodetection"])
-def test_python_2_deprecation_with_target_version(explicit: bool) -> None:
-    args = [
-        "--config",
-        str(THIS_DIR / "empty.toml"),
-        str(DATA_DIR / "python2.py"),
-        "--check",
-    ]
-    if explicit:
-        args.append("--target-version=py27")
-    with cache_dir():
-        result = BlackRunner().invoke(black.main, args)
-    assert "DEPRECATION: Python 2 support will be removed" in result.stderr
-
-
-@pytest.mark.python2
-def test_python_2_deprecation_autodetection_extended() -> None:
-    # this test has a similar construction to test_get_features_used_decorator
-    python2, non_python2 = read_data("python2_detection")
-    for python2_case in python2.split("###"):
-        node = black.lib2to3_parse(python2_case)
-        assert black.detect_target_versions(node) == {TargetVersion.PY27}, python2_case
-    for non_python2_case in non_python2.split("###"):
-        node = black.lib2to3_parse(non_python2_case)
-        assert black.detect_target_versions(node) != {
-            TargetVersion.PY27
-        }, non_python2_case
-
-
 try:
     with open(black.__file__, "r", encoding="utf-8") as _bf:
         black_source_lines = _bf.readlines()

tests/test_blackd.py

@@ -77,6 +77,9 @@ async def check(header_value: str, expected_status: int = 400) -> None:
         await check("ruby3.5")
         await check("pyi3.6")
         await check("py1.5")
+        await check("2")
+        await check("2.7")
+        await check("py2.7")
         await check("2.8")
         await check("py2.8")
         await check("3.0")
@@ -137,10 +140,6 @@ async def check(header_value: str, expected_status: int) -> None:
         await check("py36,py37", 200)
         await check("36", 200)
         await check("3.6.4", 200)
-
-        await check("2", 204)
-        await check("2.7", 204)
-        await check("py2.7", 204)
         await check("3.4", 204)
         await check("py3.4", 204)
         await check("py34,py36", 204)

tests/test_format.py

@@ -55,12 +55,6 @@
     "tupleassign",
 ]
 
-SIMPLE_CASES_PY2 = [
-    "numeric_literals_py2",
-    "python2",
-    "python2_unicode_literals",
-]
-
 EXPERIMENTAL_STRING_PROCESSING_CASES = [
     "cantfit",
     "comments7",
@@ -134,12 +128,6 @@ def check_file(filename: str, mode: black.Mode, *, data: bool = True) -> None:
     assert_format(source, expected, mode, fast=False)
 
 
-@pytest.mark.parametrize("filename", SIMPLE_CASES_PY2)
-@pytest.mark.python2
-def test_simple_format_py2(filename: str) -> None:
-    check_file(filename, DEFAULT_MODE)
-
-
 @pytest.mark.parametrize("filename", SIMPLE_CASES)
 def test_simple_format(filename: str) -> None:
     check_file(filename, DEFAULT_MODE)
@@ -219,6 +207,12 @@ def test_patma_hint() -> None:
     exc_info.match(black.parsing.PY310_HINT)
 
 
+def test_python_2_hint() -> None:
+    with pytest.raises(black.parsing.InvalidInput) as exc_info:
+        assert_format("print 'daylily'", "print 'daylily'")
+    exc_info.match(black.parsing.PY2_HINT)
+
+
 def test_docstring_no_string_normalization() -> None:
     """Like test_docstring but with string normalization off."""
     source, expected = read_data("docstring_no_string_normalization")
@@ -245,13 +239,6 @@ def test_numeric_literals_ignoring_underscores() -> None:
     assert_format(source, expected, mode)
 
 
-@pytest.mark.python2
-def test_python2_print_function() -> None:
-    source, expected = read_data("python2_print_function")
-    mode = replace(DEFAULT_MODE, target_versions={black.TargetVersion.PY27})
-    assert_format(source, expected, mode)
-
-
 def test_stub() -> None:
     mode = replace(DEFAULT_MODE, is_pyi=True)
     source, expected = read_data("stub.pyi")

tox.ini

@@ -5,7 +5,7 @@ envlist = {,ci-}py{36,37,38,39,310,py3},fuzz
 setenv = PYTHONPATH = {toxinidir}/src
 skip_install = True
 # We use `recreate=True` because otherwise, on the second run of `tox -e py`,
-# the `no_python2` tests would run with the Python2 extra dependencies installed.
+# the `no_jupyter` tests would run with the jupyter extra dependencies installed.
 # See https://github.com/psf/black/issues/2367.
 recreate = True
 deps =
@@ -15,15 +15,9 @@ deps =
 commands =
     pip install -e .[d]
     coverage erase
-    pytest tests --run-optional no_python2 \
+    pytest tests --run-optional no_jupyter \
-        --run-optional no_jupyter \
         !ci: --numprocesses auto \
         --cov {posargs}
-    pip install -e .[d,python2]
-    pytest tests --run-optional python2 \
-        --run-optional no_jupyter \
-        !ci: --numprocesses auto \
-        --cov --cov-append {posargs}
     pip install -e .[jupyter]
     pytest tests --run-optional jupyter \
         -m jupyter \
@@ -43,7 +37,7 @@ deps =
 commands =
     pip install -e .[d]
     coverage erase
-    pytest tests --run-optional no_python2 \
+    pytest tests \
         --run-optional no_jupyter \
         !ci: --numprocesses auto \
         ci: --numprocesses 1 \