diff options
Diffstat (limited to 'Lib/io.py')
-rw-r--r-- | Lib/io.py | 25 |
1 files changed, 21 insertions, 4 deletions
@@ -157,6 +157,10 @@ def open(file, mode="r", buffering=None, encoding=None, newline=None): return text +class UnsupportedOperation(ValueError, IOError): + pass + + class IOBase: """Base class for all I/O classes. @@ -177,8 +181,8 @@ class IOBase: def _unsupported(self, name: str) -> IOError: """Internal: raise an exception for unsupported operations.""" - raise IOError("%s.%s() not supported" % (self.__class__.__name__, - name)) + raise UnsupportedOperation("%s.%s() not supported" % + (self.__class__.__name__, name)) ### Positioning ### @@ -327,6 +331,8 @@ class IOBase: return res def __iter__(self): + if self.closed: + raise ValueError("__iter__ on closed file") return self def __next__(self): @@ -348,6 +354,8 @@ class IOBase: return lines def writelines(self, lines): + if self.closed: + raise ValueError("write to closed file") for line in lines: self.write(line) @@ -587,8 +595,9 @@ class _BufferedIOMixin(BufferedIOBase): self.raw.flush() def close(self): - self.flush() - self.raw.close() + if not self.closed: + self.flush() + self.raw.close() ### Inquiries ### @@ -644,6 +653,8 @@ class BytesIO(BufferedIOBase): return self.read(n) def write(self, b): + if self.closed: + raise ValueError("write to closed file") n = len(b) newpos = self._pos + n self._buffer[self._pos:newpos] = b @@ -779,6 +790,8 @@ class BufferedWriter(_BufferedIOMixin): self._write_buf = b"" def write(self, b): + if self.closed: + raise ValueError("write to closed file") if not isinstance(b, bytes): if hasattr(b, "__index__"): raise TypeError("Can't write object of type %s" % @@ -809,6 +822,8 @@ class BufferedWriter(_BufferedIOMixin): return written def flush(self): + if self.closed: + raise ValueError("flush of closed file") written = 0 try: while self._write_buf: @@ -1040,6 +1055,8 @@ class TextIOWrapper(TextIOBase): return self.buffer.isatty() def write(self, s: str): + if self.closed: + raise ValueError("write to closed file") # XXX What if we were just reading? b = s.encode(self._encoding) if isinstance(b, str): |