-import asyncio
-from concurrent.futures import Executor, ThreadPoolExecutor, ProcessPoolExecutor
-from contextlib import contextmanager
-from datetime import datetime
-from enum import Enum
import io
-from multiprocessing import Manager, freeze_support
-import os
-from pathlib import Path
-import regex as re
-import signal
+import json
+import platform
+import re
import sys
import tokenize
import traceback
+from contextlib import contextmanager
+from dataclasses import replace
+from datetime import datetime
+from enum import Enum
+from json.decoder import JSONDecodeError
+from pathlib import Path
from typing import (
Any,
Dict,
Generator,
Iterator,
List,
+ MutableMapping,
Optional,
Pattern,
+ Sequence,
Set,
Sized,
Tuple,
Union,
)
-from dataclasses import replace
import click
+from click.core import ParameterSource
+from mypy_extensions import mypyc_attr
+from pathspec import PathSpec
+from pathspec.patterns.gitwildmatch import GitWildMatchPatternError
-from black.const import DEFAULT_LINE_LENGTH, DEFAULT_INCLUDES, DEFAULT_EXCLUDES
-from black.const import STDIN_PLACEHOLDER
-from black.nodes import STARS, syms, is_simple_decorator_expression
-from black.lines import Line, EmptyLineTracker
-from black.linegen import transform_line, LineGenerator, LN
+from _black_version import version as __version__
+from black.cache import Cache, get_cache_info, read_cache, write_cache
from black.comments import normalize_fmt_off
-from black.mode import Mode, TargetVersion
-from black.mode import Feature, supports_feature, VERSION_TO_FEATURES
-from black.cache import read_cache, write_cache, get_cache_info, filter_cached, Cache
-from black.concurrency import cancel, shutdown
-from black.output import dump_to_file, diff, color_diff, out, err
-from black.report import Report, Changed
-from black.files import find_project_root, find_pyproject_toml, parse_pyproject_toml
-from black.files import gen_python_files, get_gitignore, normalize_path_maybe_ignore
-from black.files import wrap_stream_for_windows
+from black.const import (
+ DEFAULT_EXCLUDES,
+ DEFAULT_INCLUDES,
+ DEFAULT_LINE_LENGTH,
+ STDIN_PLACEHOLDER,
+)
+from black.files import (
+ find_project_root,
+ find_pyproject_toml,
+ find_user_pyproject_toml,
+ gen_python_files,
+ get_gitignore,
+ normalize_path_maybe_ignore,
+ parse_pyproject_toml,
+ wrap_stream_for_windows,
+)
+from black.handle_ipynb_magics import (
+ PYTHON_CELL_MAGICS,
+ TRANSFORMED_MAGICS,
+ jupyter_dependencies_are_installed,
+ mask_cell,
+ put_trailing_semicolon_back,
+ remove_trailing_semicolon,
+ unmask_cell,
+)
+from black.linegen import LN, LineGenerator, transform_line
+from black.lines import EmptyLineTracker, LinesBlock
+from black.mode import (
+ FUTURE_FLAG_TO_FEATURE,
+ VERSION_TO_FEATURES,
+ Feature,
+ Mode,
+ TargetVersion,
+ supports_feature,
+)
+from black.nodes import (
+ STARS,
+ is_number_token,
+ is_simple_decorator_expression,
+ is_string_token,
+ syms,
+)
+from black.output import color_diff, diff, dump_to_file, err, ipynb_diff, out
from black.parsing import InvalidInput # noqa F401
from black.parsing import lib2to3_parse, parse_ast, stringify_ast
-
-
-# lib2to3 fork
-from blib2to3.pytree import Node, Leaf
+from black.report import Changed, NothingChanged, Report
+from black.trans import iter_fexpr_spans
from blib2to3.pgen2 import token
+from blib2to3.pytree import Leaf, Node
-from _black_version import version as __version__
-
+COMPILED = Path(__file__).suffix in (".pyd", ".so")
# types
FileContent = str
NewLine = str
-class NothingChanged(UserWarning):
- """Raised when reformatted code is the same as source."""
-
-
class WriteBack(Enum):
NO = 0
YES = 1
except (OSError, ValueError) as e:
raise click.FileError(
filename=value, hint=f"Error reading configuration file: {e}"
- )
+ ) from None
if not config:
return None
ctx: click.Context,
param: click.Parameter,
value: Optional[str],
-) -> Optional[Pattern]:
+) -> Optional[Pattern[str]]:
try:
return re_compile_maybe_verbose(value) if value is not None else None
- except re.error:
- raise click.BadParameter("Not a valid regular expression")
+ except re.error as e:
+ raise click.BadParameter(f"Not a valid regular expression: {e}") from None
-@click.command(context_settings=dict(help_option_names=["-h", "--help"]))
+@click.command(
+ context_settings={"help_option_names": ["-h", "--help"]},
+ # While Click does set this field automatically using the docstring, mypyc
+ # (annoyingly) strips 'em so we need to set it here too.
+ help="The uncompromising code formatter.",
+)
@click.option("-c", "--code", type=str, help="Format the code passed in as a string.")
@click.option(
"-l",
callback=target_version_option_callback,
multiple=True,
help=(
- "Python versions that should be supported by Black's output. [default: per-file"
- " auto-detection]"
+ "Python versions that should be supported by Black's output. By default, Black"
+ " will try to infer this from the project metadata in pyproject.toml. If this"
+ " does not yield conclusive results, Black will use per-file auto-detection."
),
)
@click.option(
" when piping source on standard input)."
),
)
+@click.option(
+ "--ipynb",
+ is_flag=True,
+ help=(
+ "Format all input files like Jupyter Notebooks regardless of file extension "
+ "(useful when piping source on standard input)."
+ ),
+)
+@click.option(
+ "--python-cell-magics",
+ multiple=True,
+ help=(
+ "When processing Jupyter Notebooks, add the given magic to the list"
+ f" of known python-magics ({', '.join(sorted(PYTHON_CELL_MAGICS))})."
+ " Useful for formatting cells with custom python magics."
+ ),
+ default=[],
+)
+@click.option(
+ "-x",
+ "--skip-source-first-line",
+ is_flag=True,
+ help="Skip the first line of the source code.",
+)
@click.option(
"-S",
"--skip-string-normalization",
"--experimental-string-processing",
is_flag=True,
hidden=True,
+ help="(DEPRECATED and now included in --preview) Normalize string literals.",
+)
+@click.option(
+ "--preview",
+ is_flag=True,
help=(
- "Experimental option that performs more normalization on string literals."
- " Currently disabled because it leads to some crashes."
+ "Enable potentially disruptive style changes that may be added to Black's main"
+ " functionality in the next major release."
),
)
@click.option(
is_flag=True,
help="If --fast given, skip temporary sanity checks. [default: --safe]",
)
+@click.option(
+ "--required-version",
+ type=str,
+ help=(
+ "Require a specific version of Black to be running (useful for unifying results"
+ " across many environments e.g. with a pyproject.toml file). It can be"
+ " either a major version number or an exact version."
+ ),
+)
@click.option(
"--include",
type=str,
"editors that rely on using stdin."
),
)
+@click.option(
+ "-W",
+ "--workers",
+ type=click.IntRange(min=1),
+ default=None,
+ help="Number of parallel workers [default: number of CPUs in the system]",
+)
@click.option(
"-q",
"--quiet",
" due to exclusion patterns."
),
)
-@click.version_option(version=__version__)
+@click.version_option(
+ version=__version__,
+ message=(
+ f"%(prog)s, %(version)s (compiled: {'yes' if COMPILED else 'no'})\n"
+ f"Python ({platform.python_implementation()}) {platform.python_version()}"
+ ),
+)
@click.argument(
"src",
nargs=-1,
exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True
),
is_eager=True,
+ metavar="SRC ...",
)
@click.option(
"--config",
help="Read configuration from FILE path.",
)
@click.pass_context
-def main(
+def main( # noqa: C901
ctx: click.Context,
code: Optional[str],
line_length: int,
color: bool,
fast: bool,
pyi: bool,
+ ipynb: bool,
+ python_cell_magics: Sequence[str],
+ skip_source_first_line: bool,
skip_string_normalization: bool,
skip_magic_trailing_comma: bool,
experimental_string_processing: bool,
+ preview: bool,
quiet: bool,
verbose: bool,
- include: Pattern,
- exclude: Optional[Pattern],
- extend_exclude: Optional[Pattern],
- force_exclude: Optional[Pattern],
+ required_version: Optional[str],
+ include: Pattern[str],
+ exclude: Optional[Pattern[str]],
+ extend_exclude: Optional[Pattern[str]],
+ force_exclude: Optional[Pattern[str]],
stdin_filename: Optional[str],
+ workers: Optional[int],
src: Tuple[str, ...],
config: Optional[str],
) -> None:
"""The uncompromising code formatter."""
+ ctx.ensure_object(dict)
+
+ if src and code is not None:
+ out(
+ main.get_usage(ctx)
+ + "\n\n'SRC' and 'code' cannot be passed simultaneously."
+ )
+ ctx.exit(1)
+ if not src and code is None:
+ out(main.get_usage(ctx) + "\n\nOne of 'SRC' or 'code' is required.")
+ ctx.exit(1)
+
+ root, method = (
+ find_project_root(src, stdin_filename) if code is None else (None, None)
+ )
+ ctx.obj["root"] = root
+
+ if verbose:
+ if root:
+ out(
+ f"Identified `{root}` as project root containing a {method}.",
+ fg="blue",
+ )
+
+ normalized = [
+ (
+ (source, source)
+ if source == "-"
+ else (normalize_path_maybe_ignore(Path(source), root), source)
+ )
+ for source in src
+ ]
+ srcs_string = ", ".join(
+ [
+ (
+ f'"{_norm}"'
+ if _norm
+ else f'\033[31m"{source} (skipping - invalid)"\033[34m'
+ )
+ for _norm, source in normalized
+ ]
+ )
+ out(f"Sources to be formatted: {srcs_string}", fg="blue")
+
+ if config:
+ config_source = ctx.get_parameter_source("config")
+ user_level_config = str(find_user_pyproject_toml())
+ if config == user_level_config:
+ out(
+ (
+ "Using configuration from user-level config at "
+ f"'{user_level_config}'."
+ ),
+ fg="blue",
+ )
+ elif config_source in (
+ ParameterSource.DEFAULT,
+ ParameterSource.DEFAULT_MAP,
+ ):
+ out("Using configuration from project root.", fg="blue")
+ else:
+ out(f"Using configuration in '{config}'.", fg="blue")
+ if ctx.default_map:
+ for param, value in ctx.default_map.items():
+ out(f"{param}: {value}")
+
+ error_msg = "Oh no! 💥 💔 💥"
+ if (
+ required_version
+ and required_version != __version__
+ and required_version != __version__.split(".")[0]
+ ):
+ err(
+ f"{error_msg} The required version `{required_version}` does not match"
+ f" the running version `{__version__}`!"
+ )
+ ctx.exit(1)
+ if ipynb and pyi:
+ err("Cannot pass both `pyi` and `ipynb` flags!")
+ ctx.exit(1)
+
write_back = WriteBack.from_configuration(check=check, diff=diff, color=color)
if target_version:
versions = set(target_version)
target_versions=versions,
line_length=line_length,
is_pyi=pyi,
+ is_ipynb=ipynb,
+ skip_source_first_line=skip_source_first_line,
string_normalization=not skip_string_normalization,
magic_trailing_comma=not skip_magic_trailing_comma,
experimental_string_processing=experimental_string_processing,
+ preview=preview,
+ python_cell_magics=set(python_cell_magics),
)
- if config and verbose:
- out(f"Using configuration from {config}.", bold=False, fg="blue")
+
if code is not None:
- print(format_str(code, mode=mode))
- ctx.exit(0)
- report = Report(check=check, diff=diff, quiet=quiet, verbose=verbose)
- sources = get_sources(
- ctx=ctx,
- src=src,
- quiet=quiet,
- verbose=verbose,
- include=include,
- exclude=exclude,
- extend_exclude=extend_exclude,
- force_exclude=force_exclude,
- report=report,
- stdin_filename=stdin_filename,
- )
+ # Run in quiet mode by default with -c; the extra output isn't useful.
+ # You can still pass -v to get verbose output.
+ quiet = True
- path_empty(
- sources,
- "No Python files are present to be formatted. Nothing to do 😴",
- quiet,
- verbose,
- ctx,
- )
+ report = Report(check=check, diff=diff, quiet=quiet, verbose=verbose)
- if len(sources) == 1:
- reformat_one(
- src=sources.pop(),
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
+ if code is not None:
+ reformat_code(
+ content=code, fast=fast, write_back=write_back, mode=mode, report=report
)
else:
- reformat_many(
- sources=sources, fast=fast, write_back=write_back, mode=mode, report=report
+ try:
+ sources = get_sources(
+ ctx=ctx,
+ src=src,
+ quiet=quiet,
+ verbose=verbose,
+ include=include,
+ exclude=exclude,
+ extend_exclude=extend_exclude,
+ force_exclude=force_exclude,
+ report=report,
+ stdin_filename=stdin_filename,
+ )
+ except GitWildMatchPatternError:
+ ctx.exit(1)
+
+ path_empty(
+ sources,
+ "No Python files are present to be formatted. Nothing to do 😴",
+ quiet,
+ verbose,
+ ctx,
)
+ if len(sources) == 1:
+ reformat_one(
+ src=sources.pop(),
+ fast=fast,
+ write_back=write_back,
+ mode=mode,
+ report=report,
+ )
+ else:
+ from black.concurrency import reformat_many
+
+ reformat_many(
+ sources=sources,
+ fast=fast,
+ write_back=write_back,
+ mode=mode,
+ report=report,
+ workers=workers,
+ )
+
if verbose or not quiet:
- out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨")
- click.secho(str(report), err=True)
+ if code is None and (verbose or report.change_count or report.failure_count):
+ out()
+ out(error_msg if report.return_code else "All done! ✨ 🍰 ✨")
+ if code is None:
+ click.echo(str(report), err=True)
ctx.exit(report.return_code)
stdin_filename: Optional[str],
) -> Set[Path]:
"""Compute the set of files to be formatted."""
-
- root = find_project_root(src)
sources: Set[Path] = set()
- path_empty(src, "No Path provided. Nothing to do 😴", quiet, verbose, ctx)
+ root = ctx.obj["root"]
- if exclude is None:
- exclude = re_compile_maybe_verbose(DEFAULT_EXCLUDES)
- gitignore = get_gitignore(root)
- else:
- gitignore = None
+ using_default_exclude = exclude is None
+ exclude = re_compile_maybe_verbose(DEFAULT_EXCLUDES) if exclude is None else exclude
+ gitignore: Optional[Dict[Path, PathSpec]] = None
+ root_gitignore = get_gitignore(root)
for s in src:
if s == "-" and stdin_filename:
is_stdin = False
if is_stdin or p.is_file():
- normalized_path = normalize_path_maybe_ignore(p, root, report)
+ normalized_path = normalize_path_maybe_ignore(p, ctx.obj["root"], report)
if normalized_path is None:
continue
if is_stdin:
p = Path(f"{STDIN_PLACEHOLDER}{str(p)}")
+ if p.suffix == ".ipynb" and not jupyter_dependencies_are_installed(
+ verbose=verbose, quiet=quiet
+ ):
+ continue
+
sources.add(p)
elif p.is_dir():
+ p = root / normalize_path_maybe_ignore(p, ctx.obj["root"], report)
+ if using_default_exclude:
+ gitignore = {
+ root: root_gitignore,
+ p: get_gitignore(p),
+ }
sources.update(
gen_python_files(
p.iterdir(),
- root,
+ ctx.obj["root"],
include,
exclude,
extend_exclude,
force_exclude,
report,
gitignore,
+ verbose=verbose,
+ quiet=quiet,
)
)
elif s == "-":
"""
Exit if there is no `src` provided for formatting
"""
- if not src and (verbose or not quiet):
- out(msg)
+ if not src:
+ if verbose or not quiet:
+ out(msg)
ctx.exit(0)
+def reformat_code(
+ content: str, fast: bool, write_back: WriteBack, mode: Mode, report: Report
+) -> None:
+ """
+ Reformat and print out `content` without spawning child processes.
+ Similar to `reformat_one`, but for string content.
+
+ `fast`, `write_back`, and `mode` options are passed to
+ :func:`format_file_in_place` or :func:`format_stdin_to_stdout`.
+ """
+ path = Path("<string>")
+ try:
+ changed = Changed.NO
+ if format_stdin_to_stdout(
+ content=content, fast=fast, write_back=write_back, mode=mode
+ ):
+ changed = Changed.YES
+ report.done(path, changed)
+ except Exception as exc:
+ if report.verbose:
+ traceback.print_exc()
+ report.failed(path, str(exc))
+
+
+# diff-shades depends on being to monkeypatch this function to operate. I know it's
+# not ideal, but this shouldn't cause any issues ... hopefully. ~ichard26
+@mypyc_attr(patchable=True)
def reformat_one(
src: Path, fast: bool, write_back: WriteBack, mode: Mode, report: "Report"
) -> None:
if is_stdin:
if src.suffix == ".pyi":
mode = replace(mode, is_pyi=True)
+ elif src.suffix == ".ipynb":
+ mode = replace(mode, is_ipynb=True)
if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode):
changed = Changed.YES
else:
report.failed(src, str(exc))
-def reformat_many(
- sources: Set[Path], fast: bool, write_back: WriteBack, mode: Mode, report: "Report"
-) -> None:
- """Reformat multiple files using a ProcessPoolExecutor."""
- executor: Executor
- loop = asyncio.get_event_loop()
- worker_count = os.cpu_count()
- if sys.platform == "win32":
- # Work around https://bugs.python.org/issue26903
- worker_count = min(worker_count, 60)
- try:
- executor = ProcessPoolExecutor(max_workers=worker_count)
- except (ImportError, OSError):
- # we arrive here if the underlying system does not support multi-processing
- # like in AWS Lambda or Termux, in which case we gracefully fallback to
- # a ThreadPoolExecutor with just a single worker (more workers would not do us
- # any good due to the Global Interpreter Lock)
- executor = ThreadPoolExecutor(max_workers=1)
-
- try:
- loop.run_until_complete(
- schedule_formatting(
- sources=sources,
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
- loop=loop,
- executor=executor,
- )
- )
- finally:
- shutdown(loop)
- if executor is not None:
- executor.shutdown()
-
-
-async def schedule_formatting(
- sources: Set[Path],
- fast: bool,
- write_back: WriteBack,
- mode: Mode,
- report: "Report",
- loop: asyncio.AbstractEventLoop,
- executor: Executor,
-) -> None:
- """Run formatting of `sources` in parallel using the provided `executor`.
-
- (Use ProcessPoolExecutors for actual parallelism.)
-
- `write_back`, `fast`, and `mode` options are passed to
- :func:`format_file_in_place`.
- """
- cache: Cache = {}
- if write_back not in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
- cache = read_cache(mode)
- sources, cached = filter_cached(cache, sources)
- for src in sorted(cached):
- report.done(src, Changed.CACHED)
- if not sources:
- return
-
- cancelled = []
- sources_to_cache = []
- lock = None
- if write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
- # For diff output, we need locks to ensure we don't interleave output
- # from different processes.
- manager = Manager()
- lock = manager.Lock()
- tasks = {
- asyncio.ensure_future(
- loop.run_in_executor(
- executor, format_file_in_place, src, fast, mode, write_back, lock
- )
- ): src
- for src in sorted(sources)
- }
- pending = tasks.keys()
- try:
- loop.add_signal_handler(signal.SIGINT, cancel, pending)
- loop.add_signal_handler(signal.SIGTERM, cancel, pending)
- except NotImplementedError:
- # There are no good alternatives for these on Windows.
- pass
- while pending:
- done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED)
- for task in done:
- src = tasks.pop(task)
- if task.cancelled():
- cancelled.append(task)
- elif task.exception():
- report.failed(src, str(task.exception()))
- else:
- changed = Changed.YES if task.result() else Changed.NO
- # If the file was written back or was successfully checked as
- # well-formatted, store this information in the cache.
- if write_back is WriteBack.YES or (
- write_back is WriteBack.CHECK and changed is Changed.NO
- ):
- sources_to_cache.append(src)
- report.done(src, changed)
- if cancelled:
- await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
- if sources_to_cache:
- write_cache(cache, sources_to_cache, mode)
-
-
def format_file_in_place(
src: Path,
fast: bool,
"""
if src.suffix == ".pyi":
mode = replace(mode, is_pyi=True)
+ elif src.suffix == ".ipynb":
+ mode = replace(mode, is_ipynb=True)
then = datetime.utcfromtimestamp(src.stat().st_mtime)
+ header = b""
with open(src, "rb") as buf:
+ if mode.skip_source_first_line:
+ header = buf.readline()
src_contents, encoding, newline = decode_bytes(buf.read())
try:
dst_contents = format_file_contents(src_contents, fast=fast, mode=mode)
except NothingChanged:
return False
+ except JSONDecodeError:
+ raise ValueError(
+ f"File '{src}' cannot be parsed as valid Jupyter notebook."
+ ) from None
+ src_contents = header.decode(encoding) + src_contents
+ dst_contents = header.decode(encoding) + dst_contents
if write_back == WriteBack.YES:
with open(src, "w", encoding=encoding, newline=newline) as f:
now = datetime.utcnow()
src_name = f"{src}\t{then} +0000"
dst_name = f"{src}\t{now} +0000"
- diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
+ if mode.is_ipynb:
+ diff_contents = ipynb_diff(src_contents, dst_contents, src_name, dst_name)
+ else:
+ diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
if write_back == WriteBack.COLOR_DIFF:
diff_contents = color_diff(diff_contents)
def format_stdin_to_stdout(
- fast: bool, *, write_back: WriteBack = WriteBack.NO, mode: Mode
+ fast: bool,
+ *,
+ content: Optional[str] = None,
+ write_back: WriteBack = WriteBack.NO,
+ mode: Mode,
) -> bool:
"""Format file on stdin. Return True if changed.
+ If content is None, it's read from sys.stdin.
+
If `write_back` is YES, write reformatted code back to stdout. If it is DIFF,
write a diff to stdout. The `mode` argument is passed to
:func:`format_file_contents`.
"""
then = datetime.utcnow()
- src, encoding, newline = decode_bytes(sys.stdin.buffer.read())
+
+ if content is None:
+ src, encoding, newline = decode_bytes(sys.stdin.buffer.read())
+ else:
+ src, encoding, newline = content, "utf-8", ""
+
dst = src
try:
dst = format_file_contents(src, fast=fast, mode=mode)
sys.stdout.buffer, encoding=encoding, newline=newline, write_through=True
)
if write_back == WriteBack.YES:
+ # Make sure there's a newline after the content
+ if dst and dst[-1] != "\n":
+ dst += "\n"
f.write(dst)
elif write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
now = datetime.utcnow()
f.detach()
+def check_stability_and_equivalence(
+ src_contents: str, dst_contents: str, *, mode: Mode
+) -> None:
+ """Perform stability and equivalence checks.
+
+ Raise AssertionError if source and destination contents are not
+ equivalent, or if a second pass of the formatter would format the
+ content differently.
+ """
+ assert_equivalent(src_contents, dst_contents)
+ assert_stable(src_contents, dst_contents, mode=mode)
+
+
def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileContent:
"""Reformat contents of a file and return new contents.
valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it.
`mode` is passed to :func:`format_str`.
"""
- if not src_contents.strip():
+ if mode.is_ipynb:
+ dst_contents = format_ipynb_string(src_contents, fast=fast, mode=mode)
+ else:
+ dst_contents = format_str(src_contents, mode=mode)
+ if src_contents == dst_contents:
raise NothingChanged
- dst_contents = format_str(src_contents, mode=mode)
- if src_contents == dst_contents:
+ if not fast and not mode.is_ipynb:
+ # Jupyter notebooks will already have been checked above.
+ check_stability_and_equivalence(src_contents, dst_contents, mode=mode)
+ return dst_contents
+
+
+def validate_cell(src: str, mode: Mode) -> None:
+ """Check that cell does not already contain TransformerManager transformations,
+ or non-Python cell magics, which might cause tokenizer_rt to break because of
+ indentations.
+
+ If a cell contains ``!ls``, then it'll be transformed to
+ ``get_ipython().system('ls')``. However, if the cell originally contained
+ ``get_ipython().system('ls')``, then it would get transformed in the same way:
+
+ >>> TransformerManager().transform_cell("get_ipython().system('ls')")
+ "get_ipython().system('ls')\n"
+ >>> TransformerManager().transform_cell("!ls")
+ "get_ipython().system('ls')\n"
+
+ Due to the impossibility of safely roundtripping in such situations, cells
+ containing transformed magics will be ignored.
+ """
+ if any(transformed_magic in src for transformed_magic in TRANSFORMED_MAGICS):
+ raise NothingChanged
+ if (
+ src[:2] == "%%"
+ and src.split()[0][2:] not in PYTHON_CELL_MAGICS | mode.python_cell_magics
+ ):
raise NothingChanged
+
+def format_cell(src: str, *, fast: bool, mode: Mode) -> str:
+ """Format code in given cell of Jupyter notebook.
+
+ General idea is:
+
+ - if cell has trailing semicolon, remove it;
+ - if cell has IPython magics, mask them;
+ - format cell;
+ - reinstate IPython magics;
+ - reinstate trailing semicolon (if originally present);
+ - strip trailing newlines.
+
+ Cells with syntax errors will not be processed, as they
+ could potentially be automagics or multi-line magics, which
+ are currently not supported.
+ """
+ validate_cell(src, mode)
+ src_without_trailing_semicolon, has_trailing_semicolon = remove_trailing_semicolon(
+ src
+ )
+ try:
+ masked_src, replacements = mask_cell(src_without_trailing_semicolon)
+ except SyntaxError:
+ raise NothingChanged from None
+ masked_dst = format_str(masked_src, mode=mode)
if not fast:
- assert_equivalent(src_contents, dst_contents)
-
- # Forced second pass to work around optional trailing commas (becoming
- # forced trailing commas on pass 2) interacting differently with optional
- # parentheses. Admittedly ugly.
- dst_contents_pass2 = format_str(dst_contents, mode=mode)
- if dst_contents != dst_contents_pass2:
- dst_contents = dst_contents_pass2
- assert_equivalent(src_contents, dst_contents, pass_num=2)
- assert_stable(src_contents, dst_contents, mode=mode)
- # Note: no need to explicitly call `assert_stable` if `dst_contents` was
- # the same as `dst_contents_pass2`.
- return dst_contents
+ check_stability_and_equivalence(masked_src, masked_dst, mode=mode)
+ dst_without_trailing_semicolon = unmask_cell(masked_dst, replacements)
+ dst = put_trailing_semicolon_back(
+ dst_without_trailing_semicolon, has_trailing_semicolon
+ )
+ dst = dst.rstrip("\n")
+ if dst == src:
+ raise NothingChanged from None
+ return dst
+
+
+def validate_metadata(nb: MutableMapping[str, Any]) -> None:
+ """If notebook is marked as non-Python, don't format it.
+
+ All notebook metadata fields are optional, see
+ https://nbformat.readthedocs.io/en/latest/format_description.html. So
+ if a notebook has empty metadata, we will try to parse it anyway.
+ """
+ language = nb.get("metadata", {}).get("language_info", {}).get("name", None)
+ if language is not None and language != "python":
+ raise NothingChanged from None
+
+
+def format_ipynb_string(src_contents: str, *, fast: bool, mode: Mode) -> FileContent:
+ """Format Jupyter notebook.
+
+ Operate cell-by-cell, only on code cells, only for Python notebooks.
+ If the ``.ipynb`` originally had a trailing newline, it'll be preserved.
+ """
+ if not src_contents:
+ raise NothingChanged
+
+ trailing_newline = src_contents[-1] == "\n"
+ modified = False
+ nb = json.loads(src_contents)
+ validate_metadata(nb)
+ for cell in nb["cells"]:
+ if cell.get("cell_type", None) == "code":
+ try:
+ src = "".join(cell["source"])
+ dst = format_cell(src, fast=fast, mode=mode)
+ except NothingChanged:
+ pass
+ else:
+ cell["source"] = dst.splitlines(keepends=True)
+ modified = True
+ if modified:
+ dst_contents = json.dumps(nb, indent=1, ensure_ascii=False)
+ if trailing_newline:
+ dst_contents = dst_contents + "\n"
+ return dst_contents
+ else:
+ raise NothingChanged
-def format_str(src_contents: str, *, mode: Mode) -> FileContent:
+def format_str(src_contents: str, *, mode: Mode) -> str:
"""Reformat a string and return new contents.
`mode` determines formatting options, such as how many characters per line are
hey
"""
+ dst_contents = _format_str_once(src_contents, mode=mode)
+ # Forced second pass to work around optional trailing commas (becoming
+ # forced trailing commas on pass 2) interacting differently with optional
+ # parentheses. Admittedly ugly.
+ if src_contents != dst_contents:
+ return _format_str_once(dst_contents, mode=mode)
+ return dst_contents
+
+
+def _format_str_once(src_contents: str, *, mode: Mode) -> str:
src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions)
- dst_contents = []
- future_imports = get_future_imports(src_node)
+ dst_blocks: List[LinesBlock] = []
if mode.target_versions:
versions = mode.target_versions
else:
- versions = detect_target_versions(src_node)
+ future_imports = get_future_imports(src_node)
+ versions = detect_target_versions(src_node, future_imports=future_imports)
+
+ context_manager_features = {
+ feature
+ for feature in {Feature.PARENTHESIZED_CONTEXT_MANAGERS}
+ if supports_feature(versions, feature)
+ }
normalize_fmt_off(src_node)
- lines = LineGenerator(
- 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
+ lines = LineGenerator(mode=mode, features=context_manager_features)
+ elt = EmptyLineTracker(mode=mode)
split_line_features = {
feature
for feature in {Feature.TRAILING_COMMA_IN_CALL, Feature.TRAILING_COMMA_IN_DEF}
if supports_feature(versions, feature)
}
+ block: Optional[LinesBlock] = None
for current_line in lines.visit(src_node):
- dst_contents.append(str(empty_line) * after)
- before, after = elt.maybe_empty_lines(current_line)
- dst_contents.append(str(empty_line) * before)
+ block = elt.maybe_empty_lines(current_line)
+ dst_blocks.append(block)
for line in transform_line(
current_line, mode=mode, features=split_line_features
):
- dst_contents.append(str(line))
+ block.content_lines.append(str(line))
+ if dst_blocks:
+ dst_blocks[-1].after = 0
+ dst_contents = []
+ for block in dst_blocks:
+ dst_contents.extend(block.all_lines())
+ if not dst_contents:
+ # Use decode_bytes to retrieve the correct source newline (CRLF or LF),
+ # and check if normalized_content has more than one line
+ normalized_content, _, newline = decode_bytes(src_contents.encode("utf-8"))
+ if "\n" in normalized_content:
+ return newline
+ return ""
return "".join(dst_contents)
return tiow.read(), encoding, newline
-def get_features_used(node: Node) -> Set[Feature]:
+def get_features_used( # noqa: C901
+ node: Node, *, future_imports: Optional[Set[str]] = None
+) -> Set[Feature]:
"""Return a set of (relatively) new Python features used in this file.
Currently looking for:
- f-strings;
+ - self-documenting expressions in f-strings (f"{x=}");
- underscores in numeric literals;
- trailing commas after * or ** in function signatures and calls;
- positional only arguments in function signatures and lambdas;
- assignment expression;
- relaxed decorator syntax;
+ - usage of __future__ flags (annotations);
+ - print / exec statements;
+ - parenthesized context managers;
+ - match statements;
+ - except* clause;
+ - variadic generics;
"""
features: Set[Feature] = set()
+ if future_imports:
+ features |= {
+ FUTURE_FLAG_TO_FEATURE[future_import]
+ for future_import in future_imports
+ if future_import in FUTURE_FLAG_TO_FEATURE
+ }
+
for n in node.pre_order():
- if n.type == token.STRING:
- value_head = n.value[:2] # type: ignore
+ if is_string_token(n):
+ value_head = n.value[:2]
if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}:
features.add(Feature.F_STRINGS)
-
- elif n.type == token.NUMBER:
- if "_" in n.value: # type: ignore
+ if Feature.DEBUG_F_STRINGS not in features:
+ for span_beg, span_end in iter_fexpr_spans(n.value):
+ if n.value[span_beg : span_end - 1].rstrip().endswith("="):
+ features.add(Feature.DEBUG_F_STRINGS)
+ break
+
+ elif is_number_token(n):
+ if "_" in n.value:
features.add(Feature.NUMERIC_UNDERSCORES)
elif n.type == token.SLASH:
- if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}:
+ if n.parent and n.parent.type in {
+ syms.typedargslist,
+ syms.arglist,
+ syms.varargslist,
+ }:
features.add(Feature.POS_ONLY_ARGUMENTS)
elif n.type == token.COLONEQUAL:
if argch.type in STARS:
features.add(feature)
+ elif (
+ n.type in {syms.return_stmt, syms.yield_expr}
+ and len(n.children) >= 2
+ and n.children[1].type == syms.testlist_star_expr
+ and any(child.type == syms.star_expr for child in n.children[1].children)
+ ):
+ features.add(Feature.UNPACKING_ON_FLOW)
+
+ elif (
+ n.type == syms.annassign
+ and len(n.children) >= 4
+ and n.children[3].type == syms.testlist_star_expr
+ ):
+ features.add(Feature.ANN_ASSIGN_EXTENDED_RHS)
+
+ elif (
+ n.type == syms.with_stmt
+ and len(n.children) > 2
+ and n.children[1].type == syms.atom
+ ):
+ atom_children = n.children[1].children
+ if (
+ len(atom_children) == 3
+ and atom_children[0].type == token.LPAR
+ and atom_children[1].type == syms.testlist_gexp
+ and atom_children[2].type == token.RPAR
+ ):
+ features.add(Feature.PARENTHESIZED_CONTEXT_MANAGERS)
+
+ elif n.type == syms.match_stmt:
+ features.add(Feature.PATTERN_MATCHING)
+
+ elif (
+ n.type == syms.except_clause
+ and len(n.children) >= 2
+ and n.children[1].type == token.STAR
+ ):
+ features.add(Feature.EXCEPT_STAR)
+
+ elif n.type in {syms.subscriptlist, syms.trailer} and any(
+ child.type == syms.star_expr for child in n.children
+ ):
+ features.add(Feature.VARIADIC_GENERICS)
+
+ elif (
+ n.type == syms.tname_star
+ and len(n.children) == 3
+ and n.children[2].type == syms.star_expr
+ ):
+ features.add(Feature.VARIADIC_GENERICS)
+
return features
-def detect_target_versions(node: Node) -> Set[TargetVersion]:
+def detect_target_versions(
+ node: Node, *, future_imports: Optional[Set[str]] = None
+) -> Set[TargetVersion]:
"""Detect the version to target based on the nodes used."""
- features = get_features_used(node)
+ features = get_features_used(node, future_imports=future_imports)
return {
version for version in TargetVersion if features <= VERSION_TO_FEATURES[version]
}
return imports
-def assert_equivalent(src: str, dst: str, *, pass_num: int = 1) -> None:
+def assert_equivalent(src: str, dst: str) -> None:
"""Raise AssertionError if `src` and `dst` aren't equivalent."""
try:
src_ast = parse_ast(src)
except Exception as exc:
raise AssertionError(
- "cannot use --safe with this file; failed to parse source file. AST"
- f" error message: {exc}"
- )
+ "cannot use --safe with this file; failed to parse source file AST: "
+ f"{exc}\n"
+ "This could be caused by running Black with an older Python version "
+ "that does not support new syntax used in your source file."
+ ) from exc
try:
dst_ast = parse_ast(dst)
except Exception as exc:
log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
raise AssertionError(
- f"INTERNAL ERROR: Black produced invalid code on pass {pass_num}: {exc}. "
+ f"INTERNAL ERROR: Black produced invalid code: {exc}. "
"Please report a bug on https://github.com/psf/black/issues. "
f"This invalid output might be helpful: {log}"
) from None
log = dump_to_file(diff(src_ast_str, dst_ast_str, "src", "dst"))
raise AssertionError(
"INTERNAL ERROR: Black produced code that is not equivalent to the"
- f" source on pass {pass_num}. Please report a bug on "
+ " source. Please report a bug on "
f"https://github.com/psf/black/issues. This diff might be helpful: {log}"
) from None
def assert_stable(src: str, dst: str, mode: Mode) -> None:
"""Raise AssertionError if `dst` reformats differently the second time."""
- newdst = format_str(dst, mode=mode)
+ # We shouldn't call format_str() here, because that formats the string
+ # twice and may hide a bug where we bounce back and forth between two
+ # versions.
+ newdst = _format_str_once(dst, mode=mode)
if dst != newdst:
log = dump_to_file(
str(mode),
def patch_click() -> None:
- """Make Click not crash.
+ """Make Click not crash on Python 3.6 with LANG=C.
On certain misconfigured environments, Python 3 selects the ASCII encoding as the
default which restricts paths that it can access during the lifetime of the
file paths is minimal since it's Python source code. Moreover, this crash was
spurious on Python 3.7 thanks to PEP 538 and PEP 540.
"""
+ modules: List[Any] = []
try:
from click import core
+ except ImportError:
+ pass
+ else:
+ modules.append(core)
+ try:
+ # Removed in Click 8.1.0 and newer; we keep this around for users who have
+ # older versions installed.
from click import _unicodefun # type: ignore
- except ModuleNotFoundError:
- return
+ except ImportError:
+ pass
+ else:
+ modules.append(_unicodefun)
- for module in (core, _unicodefun):
+ for module in modules:
if hasattr(module, "_verify_python3_env"):
module._verify_python3_env = lambda: None
+ if hasattr(module, "_verify_python_env"):
+ module._verify_python_env = lambda: None
def patched_main() -> None:
- freeze_support()
+ # PyInstaller patches multiprocessing to need freeze_support() even in non-Windows
+ # environments so just assume we always need to call it if frozen.
+ if getattr(sys, "frozen", False):
+ from multiprocessing import freeze_support
+
+ freeze_support()
+
patch_click()
main()