]> git.madduck.net Git - etc/vim.git/blobdiff - src/black/__init__.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Remove `blackcellmagic` reference (#2477)
[etc/vim.git] / src / black / __init__.py
index 51384fb08da5edadc3d783425cbfb448f7306afe..d033e01141aa9f4f77ba16559c0697e14d81b6a6 100644 (file)
@@ -1,4 +1,6 @@
 import asyncio
+from json.decoder import JSONDecodeError
+import json
 from concurrent.futures import Executor, ThreadPoolExecutor, ProcessPoolExecutor
 from contextlib import contextmanager
 from datetime import datetime
@@ -7,6 +9,7 @@ import io
 from multiprocessing import Manager, freeze_support
 import os
 from pathlib import Path
+from pathspec.patterns.gitwildmatch import GitWildMatchPatternError
 import regex as re
 import signal
 import sys
@@ -18,6 +21,7 @@ from typing import (
     Generator,
     Iterator,
     List,
+    MutableMapping,
     Optional,
     Pattern,
     Set,
@@ -39,13 +43,21 @@ 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, maybe_install_uvloop
-from black.output import dump_to_file, diff, color_diff, out, err
-from black.report import Report, Changed
+from black.output import dump_to_file, ipynb_diff, diff, color_diff, out, err
+from black.report import Report, Changed, NothingChanged
 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.parsing import InvalidInput  # noqa F401
 from black.parsing import lib2to3_parse, parse_ast, stringify_ast
+from black.handle_ipynb_magics import (
+    mask_cell,
+    unmask_cell,
+    remove_trailing_semicolon,
+    put_trailing_semicolon_back,
+    TRANSFORMED_MAGICS,
+    jupyter_dependencies_are_installed,
+)
 
 
 # lib2to3 fork
@@ -60,10 +72,6 @@ Encoding = str
 NewLine = str
 
 
-class NothingChanged(UserWarning):
-    """Raised when reformatted code is the same as source."""
-
-
 class WriteBack(Enum):
     NO = 0
     YES = 1
@@ -196,6 +204,14 @@ def validate_regex(
         " 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(
     "-S",
     "--skip-string-normalization",
@@ -355,6 +371,7 @@ def main(
     color: bool,
     fast: bool,
     pyi: bool,
+    ipynb: bool,
     skip_string_normalization: bool,
     skip_magic_trailing_comma: bool,
     experimental_string_processing: bool,
@@ -380,6 +397,9 @@ def main(
             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:
@@ -391,6 +411,7 @@ def main(
         target_versions=versions,
         line_length=line_length,
         is_pyi=pyi,
+        is_ipynb=ipynb,
         string_normalization=not skip_string_normalization,
         magic_trailing_comma=not skip_magic_trailing_comma,
         experimental_string_processing=experimental_string_processing,
@@ -408,18 +429,21 @@ def main(
             content=code, fast=fast, write_back=write_back, mode=mode, report=report
         )
     else:
-        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,
-        )
+        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,
@@ -504,6 +528,11 @@ def get_sources(
             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():
             sources.update(
@@ -516,6 +545,8 @@ def get_sources(
                     force_exclude,
                     report,
                     gitignore,
+                    verbose=verbose,
+                    quiet=quiet,
                 )
             )
         elif s == "-":
@@ -585,6 +616,8 @@ def reformat_one(
         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:
@@ -733,6 +766,8 @@ def format_file_in_place(
     """
     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)
     with open(src, "rb") as buf:
@@ -741,6 +776,8 @@ def format_file_in_place(
         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.")
 
     if write_back == WriteBack.YES:
         with open(src, "w", encoding=encoding, newline=newline) as f:
@@ -749,7 +786,10 @@ def format_file_in_place(
         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)
@@ -819,6 +859,29 @@ def format_stdin_to_stdout(
         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)
+
+    # 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`.
+
+
 def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileContent:
     """Reformat contents of a file and return new contents.
 
@@ -829,26 +892,116 @@ def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileCo
     if not src_contents.strip():
         raise NothingChanged
 
-    dst_contents = format_str(src_contents, mode=mode)
+    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
 
-    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`.
+    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) -> None:
+    """Check that cell does not already contain TransformerManager transformations.
+
+    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
+
+
+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)
+    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
+    masked_dst = format_str(masked_src, mode=mode)
+    if not fast:
+        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
+    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
+
+
+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.
+    """
+    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:
     """Reformat a string and return new contents.