Module isort.io
Defines any IO utilities used by isort
None
View Source
"""Defines any IO utilities used by isort"""
import re
import tokenize
from contextlib import contextmanager
from io import BytesIO, StringIO, TextIOWrapper
from pathlib import Path
from typing import Any, Callable, Iterator, TextIO, Union
from isort._future import dataclass
from isort.exceptions import UnsupportedEncoding
_ENCODING_PATTERN = re.compile(rb"^[ \t\f]*#.*?coding[:=][ \t]*([-_.a-zA-Z0-9]+)")
@dataclass(frozen=True)
class File:
stream: TextIO
path: Path
encoding: str
@staticmethod
def detect_encoding(filename: Union[str, Path], readline: Callable[[], bytes]) -> str:
try:
return tokenize.detect_encoding(readline)[0]
except Exception:
raise UnsupportedEncoding(filename)
@staticmethod
def from_contents(contents: str, filename: str) -> "File":
encoding = File.detect_encoding(filename, BytesIO(contents.encode("utf-8")).readline)
return File( # type: ignore
stream=StringIO(contents), path=Path(filename).resolve(), encoding=encoding
)
@property
def extension(self) -> str:
return self.path.suffix.lstrip(".")
@staticmethod
def _open(filename: Union[str, Path]) -> TextIOWrapper:
"""Open a file in read only mode using the encoding detected by
detect_encoding().
"""
buffer = open(filename, "rb")
try:
encoding = File.detect_encoding(filename, buffer.readline)
buffer.seek(0)
text = TextIOWrapper(buffer, encoding, line_buffering=True, newline="")
text.mode = "r" # type: ignore
return text
except Exception:
buffer.close()
raise
@staticmethod
@contextmanager
def read(filename: Union[str, Path]) -> Iterator["File"]:
file_path = Path(filename).resolve()
stream = None
try:
stream = File._open(file_path)
yield File(stream=stream, path=file_path, encoding=stream.encoding) # type: ignore
finally:
if stream is not None:
stream.close()
class _EmptyIO(StringIO):
def write(self, *args: Any, **kwargs: Any) -> None: # type: ignore # skipcq: PTC-W0049
pass
Empty = _EmptyIO()
Variables
Empty
Classes
File
class File(
stream: <class 'TextIO'>,
path: pathlib.Path,
encoding: str
)
View Source
@dataclass(frozen=True)
class File:
stream: TextIO
path: Path
encoding: str
@staticmethod
def detect_encoding(filename: Union[str, Path], readline: Callable[[], bytes]) -> str:
try:
return tokenize.detect_encoding(readline)[0]
except Exception:
raise UnsupportedEncoding(filename)
@staticmethod
def from_contents(contents: str, filename: str) -> "File":
encoding = File.detect_encoding(filename, BytesIO(contents.encode("utf-8")).readline)
return File( # type: ignore
stream=StringIO(contents), path=Path(filename).resolve(), encoding=encoding
)
@property
def extension(self) -> str:
return self.path.suffix.lstrip(".")
@staticmethod
def _open(filename: Union[str, Path]) -> TextIOWrapper:
"""Open a file in read only mode using the encoding detected by
detect_encoding().
"""
buffer = open(filename, "rb")
try:
encoding = File.detect_encoding(filename, buffer.readline)
buffer.seek(0)
text = TextIOWrapper(buffer, encoding, line_buffering=True, newline="")
text.mode = "r" # type: ignore
return text
except Exception:
buffer.close()
raise
@staticmethod
@contextmanager
def read(filename: Union[str, Path]) -> Iterator["File"]:
file_path = Path(filename).resolve()
stream = None
try:
stream = File._open(file_path)
yield File(stream=stream, path=file_path, encoding=stream.encoding) # type: ignore
finally:
if stream is not None:
stream.close()
Static methods
detect_encoding
def detect_encoding(
filename: Union[str, pathlib.Path],
readline: Callable[[], bytes]
) -> str
View Source
@staticmethod
def detect_encoding(filename: Union[str, Path], readline: Callable[[], bytes]) -> str:
try:
return tokenize.detect_encoding(readline)[0]
except Exception:
raise UnsupportedEncoding(filename)
from_contents
def from_contents(
contents: str,
filename: str
) -> 'File'
View Source
@staticmethod
def from_contents(contents: str, filename: str) -> "File":
encoding = File.detect_encoding(filename, BytesIO(contents.encode("utf-8")).readline)
return File( # type: ignore
stream=StringIO(contents), path=Path(filename).resolve(), encoding=encoding
)
read
def read(
filename: Union[str, pathlib.Path]
) -> Iterator[ForwardRef('File')]
View Source
@staticmethod
@contextmanager
def read(filename: Union[str, Path]) -> Iterator["File"]:
file_path = Path(filename).resolve()
stream = None
try:
stream = File._open(file_path)
yield File(stream=stream, path=file_path, encoding=stream.encoding) # type: ignore
finally:
if stream is not None:
stream.close()
Instance variables
extension