craftbeerpi4-pione/venv3/lib/python3.7/site-packages/pandas/io/orc.py
2021-03-03 23:49:41 +01:00

56 lines
1.6 KiB
Python

""" orc compat """
import distutils
from typing import TYPE_CHECKING, List, Optional
from pandas._typing import FilePathOrBuffer
from pandas.io.common import get_filepath_or_buffer
if TYPE_CHECKING:
from pandas import DataFrame
def read_orc(
path: FilePathOrBuffer, columns: Optional[List[str]] = None, **kwargs,
) -> "DataFrame":
"""
Load an ORC object from the file path, returning a DataFrame.
.. versionadded:: 1.0.0
Parameters
----------
path : str, path object or file-like object
Any valid string path is acceptable. The string could be a URL. Valid
URL schemes include http, ftp, s3, and file. For file URLs, a host is
expected. A local file could be:
``file://localhost/path/to/table.orc``.
If you want to pass in a path object, pandas accepts any
``os.PathLike``.
By file-like object, we refer to objects with a ``read()`` method,
such as a file handler (e.g. via builtin ``open`` function)
or ``StringIO``.
columns : list, default None
If not None, only these columns will be read from the file.
**kwargs
Any additional kwargs are passed to pyarrow.
Returns
-------
DataFrame
"""
# we require a newer version of pyarrow than we support for parquet
import pyarrow
if distutils.version.LooseVersion(pyarrow.__version__) < "0.13.0":
raise ImportError("pyarrow must be >= 0.13.0 for read_orc")
import pyarrow.orc
path, _, _, _ = get_filepath_or_buffer(path)
orc_file = pyarrow.orc.ORCFile(path)
result = orc_file.read(columns=columns, **kwargs).to_pandas()
return result