address comments

python/cudf/cudf/_lib/pylibcudf/io/types.pyx

@@ -158,7 +158,7 @@ cdef cppclass iobase_data_sink(data_sink):
  this.buf = buf_
 
  void host_write(const void * data, size_t size) with gil:
- if isinstance(buf, io.StringIO):
+ if isinstance(buf, io.TextIOBase):
  buf.write(PyMemoryView_FromMemory(<char*>data, size, PyBUF_READ)
  .tobytes().decode())
  else:
@@ -200,28 +200,26 @@ cdef class SinkInfo:
  )
  data_sinks.push_back(self.sink_storage.back().get())
  self.c_obj = sink_info(data_sinks)
- elif isinstance(sinks[0], io.TextIOBase):
+ elif isinstance(sinks[0], io.IOBase):
  data_sinks.reserve(len(sinks))
  for s in sinks:
  # Files opened in text mode expect writes to be str rather than
  # bytes, which requires conversion from utf-8. If the underlying
  # buffer is utf-8, we can bypass this conversion by writing
  # directly to it.
- if codecs.lookup(s.encoding).name not in {"utf-8", "ascii"}:
+ if (
+ isinstance(s, io.TextIOBase) and
+ codecs.lookup(s.encoding).name not in {
+ "utf-8",
+ "ascii",
+ }
+ ):
  raise NotImplementedError(f"Unsupported encoding {s.encoding}")
  self.sink_storage.push_back(
  unique_ptr[data_sink](new iobase_data_sink(s.buffer))
  )
  data_sinks.push_back(self.sink_storage.back().get())
  self.c_obj = sink_info(data_sinks)
- elif isinstance(sinks[0], io.IOBase):
- data_sinks.reserve(len(sinks))
- for s in sinks:
- self.sink_storage.push_back(
- unique_ptr[data_sink](new iobase_data_sink(s))
- )
- data_sinks.push_back(self.sink_storage.back().get())
- self.c_obj = sink_info(data_sinks)
  elif isinstance(sinks[0], (basestring, os.PathLike)):
  paths.reserve(len(sinks))
  for s in sinks: