135 lines
3.7 KiB
Python
135 lines
3.7 KiB
Python
|
""" feather-format compat """
|
||
|
|
from __future__ import annotations
|
||
|
|
|
||
|
|
from typing import (
|
||
|
|
Hashable,
|
||
|
|
Sequence,
|
||
|
|
)
|
||
|
|
|
||
|
|
from pandas._typing import (
|
||
|
|
FilePath,
|
||
|
|
ReadBuffer,
|
||
|
|
StorageOptions,
|
||
|
|
WriteBuffer,
|
||
|
|
)
|
||
|
|
from pandas.compat._optional import import_optional_dependency
|
||
|
|
from pandas.util._decorators import doc
|
||
|
|
|
||
|
|
from pandas.core.api import (
|
||
|
|
DataFrame,
|
||
|
|
Int64Index,
|
||
|
|
RangeIndex,
|
||
|
|
)
|
||
|
|
from pandas.core.shared_docs import _shared_docs
|
||
|
|
|
||
|
|
from pandas.io.common import get_handle
|
||
|
|
|
||
|
|
|
||
|
|
@doc(storage_options=_shared_docs["storage_options"])
|
||
|
|
def to_feather(
|
||
|
|
df: DataFrame,
|
||
|
|
path: FilePath | WriteBuffer[bytes],
|
||
|
|
storage_options: StorageOptions = None,
|
||
|
|
**kwargs,
|
||
|
|
) -> None:
|
||
|
|
"""
|
||
|
|
Write a DataFrame to the binary Feather format.
|
||
|
|
|
||
|
|
Parameters
|
||
|
|
----------
|
||
|
|
df : DataFrame
|
||
|
|
path : str, path object, or file-like object
|
||
|
|
{storage_options}
|
||
|
|
|
||
|
|
.. versionadded:: 1.2.0
|
||
|
|
|
||
|
|
**kwargs :
|
||
|
|
Additional keywords passed to `pyarrow.feather.write_feather`.
|
||
|
|
|
||
|
|
.. versionadded:: 1.1.0
|
||
|
|
"""
|
||
|
|
import_optional_dependency("pyarrow")
|
||
|
|
from pyarrow import feather
|
||
|
|
|
||
|
|
if not isinstance(df, DataFrame):
|
||
|
|
raise ValueError("feather only support IO with DataFrames")
|
||
|
|
|
||
|
|
valid_types = {"string", "unicode"}
|
||
|
|
|
||
|
|
# validate index
|
||
|
|
# --------------
|
||
|
|
|
||
|
|
# validate that we have only a default index
|
||
|
|
# raise on anything else as we don't serialize the index
|
||
|
|
|
||
|
|
if not isinstance(df.index, (Int64Index, RangeIndex)):
|
||
|
|
typ = type(df.index)
|
||
|
|
raise ValueError(
|
||
|
|
f"feather does not support serializing {typ} "
|
||
|
|
"for the index; you can .reset_index() to make the index into column(s)"
|
||
|
|
)
|
||
|
|
|
||
|
|
if not df.index.equals(RangeIndex.from_range(range(len(df)))):
|
||
|
|
raise ValueError(
|
||
|
|
"feather does not support serializing a non-default index for the index; "
|
||
|
|
"you can .reset_index() to make the index into column(s)"
|
||
|
|
)
|
||
|
|
|
||
|
|
if df.index.name is not None:
|
||
|
|
raise ValueError(
|
||
|
|
"feather does not serialize index meta-data on a default index"
|
||
|
|
)
|
||
|
|
|
||
|
|
# validate columns
|
||
|
|
# ----------------
|
||
|
|
|
||
|
|
# must have value column names (strings only)
|
||
|
|
if df.columns.inferred_type not in valid_types:
|
||
|
|
raise ValueError("feather must have string column names")
|
||
|
|
|
||
|
|
with get_handle(
|
||
|
|
path, "wb", storage_options=storage_options, is_text=False
|
||
|
|
) as handles:
|
||
|
|
feather.write_feather(df, handles.handle, **kwargs)
|
||
|
|
|
||
|
|
|
||
|
|
@doc(storage_options=_shared_docs["storage_options"])
|
||
|
|
def read_feather(
|
||
|
|
path: FilePath | ReadBuffer[bytes],
|
||
|
|
columns: Sequence[Hashable] | None = None,
|
||
|
|
use_threads: bool = True,
|
||
|
|
storage_options: StorageOptions = None,
|
||
|
|
):
|
||
|
|
"""
|
||
|
|
Load a feather-format object from the file path.
|
||
|
|
|
||
|
|
Parameters
|
||
|
|
----------
|
||
|
|
path : str, path object, or file-like object
|
||
|
|
String, path object (implementing ``os.PathLike[str]``), or file-like
|
||
|
|
object implementing a binary ``read()`` function. 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.feather``.
|
||
|
|
columns : sequence, default None
|
||
|
|
If not provided, all columns are read.
|
||
|
|
use_threads : bool, default True
|
||
|
|
Whether to parallelize reading using multiple threads.
|
||
|
|
{storage_options}
|
||
|
|
|
||
|
|
.. versionadded:: 1.2.0
|
||
|
|
|
||
|
|
Returns
|
||
|
|
-------
|
||
|
|
type of object stored in file
|
||
|
|
"""
|
||
|
|
import_optional_dependency("pyarrow")
|
||
|
|
from pyarrow import feather
|
||
|
|
|
||
|
|
with get_handle(
|
||
|
|
path, "rb", storage_options=storage_options, is_text=False
|
||
|
|
) as handles:
|
||
|
|
|
||
|
|
return feather.read_feather(
|
||
|
|
handles.handle, columns=columns, use_threads=bool(use_threads)
|
||
|
|
)
|