file_proxy.py

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import io
from typing import IO, TYPE_CHECKING, Any, List
 
from .ansi import AnsiDecoder
from .text import Text
 
if TYPE_CHECKING:
    from .console import Console
 
 
class FileProxy(io.TextIOBase):
    """Wraps a file (e.g. sys.stdout) and redirects writes to a console."""
 
    def __init__(self, console: "Console", file: IO[str]) -> None:
        self.__console = console
        self.__file = file
        self.__buffer: List[str] = []
        self.__ansi_decoder = AnsiDecoder()
 
    @property
    def rich_proxied_file(self) -> IO[str]:
        """Get proxied file."""
        return self.__file
 
    def __getattr__(self, name: str) -> Any:
        return getattr(self.__file, name)
 
    def write(self, text: str) -> int:
        if not isinstance(text, str):
            raise TypeError(f"write() argument must be str, not {type(text).__name__}")
        buffer = self.__buffer
        lines: List[str] = []
        while text:
            line, new_line, text = text.partition("\n")
            if new_line:
                lines.append("".join(buffer) + line)
                buffer.clear()
            else:
                buffer.append(line)
                break
        if lines:
            console = self.__console
            with console:
                output = Text("\n").join(
                    self.__ansi_decoder.decode_line(line) for line in lines
                )
                console.print(output)
        return len(text)
 
    def flush(self) -> None:
        output = "".join(self.__buffer)
        if output:
            self.__console.print(output)
        del self.__buffer[:]
 
    def fileno(self) -> int:
        return self.__file.fileno()