import posixpath
from wfdb.io import _url
from wfdb.io.download import config
def _open_file(
pn_dir,
file_name,
mode="r",
*,
buffering=-1,
encoding=None,
errors=None,
newline=None,
check_access=False,
):
"""
Open a data file as a random-access file object.
See the documentation of `open` and `wfdb.io._url.openurl` for details
about the `mode`, `buffering`, `encoding`, `errors`, and `newline`
parameters.
Parameters
----------
pn_dir : str or None
The PhysioNet database directory where the file is stored, or None
if file_name is a local path.
file_name : str
The name of the file, either as a local filesystem path (if
`pn_dir` is None) or a URL path (if `pn_dir` is a string.)
mode : str, optional
The standard I/O mode for the file ("r" by default). If `pn_dir`
is not None, this must be "r", "rt", or "rb".
buffering : int, optional
Buffering policy.
encoding : str, optional
Name of character encoding used in text mode.
errors : str, optional
Error handling strategy used in text mode.
newline : str, optional
Newline translation mode used in text mode.
check_access : bool, optional
If true, raise an exception immediately if the file does not
exist or is not accessible.
"""
if pn_dir is None:
return open(
file_name,
mode,
buffering=buffering,
encoding=encoding,
errors=errors,
newline=newline,
)
else:
url = posixpath.join(config.db_index_url, pn_dir, file_name)
return _url.openurl(
url,
mode,
buffering=buffering,
encoding=encoding,
errors=errors,
newline=newline,
check_access=check_access,
)