| # Licensed to the Apache Software Foundation (ASF) under one |
| # or more contributor license agreements. See the NOTICE file |
| # distributed with this work for additional information |
| # regarding copyright ownership. The ASF licenses this file |
| # to you under the Apache License, Version 2.0 (the |
| # "License"); you may not use this file except in compliance |
| # with the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, |
| # software distributed under the License is distributed on an |
| # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| # KIND, either express or implied. See the License for the |
| # specific language governing permissions and limitations |
| # under the License. |
| |
| # --------------------------------------------------------------------- |
| # Implement Feather file format |
| |
| |
| class FeatherError(Exception): |
| pass |
| |
| |
| def write_feather(Table table, object dest, compression=None, |
| compression_level=None, chunksize=None, version=2): |
| cdef shared_ptr[COutputStream] sink |
| get_writer(dest, &sink) |
| |
| cdef CFeatherProperties properties |
| if version == 2: |
| properties.version = kFeatherV2Version |
| else: |
| properties.version = kFeatherV1Version |
| |
| if compression == 'zstd': |
| properties.compression = CCompressionType_ZSTD |
| elif compression == 'lz4': |
| properties.compression = CCompressionType_LZ4_FRAME |
| else: |
| properties.compression = CCompressionType_UNCOMPRESSED |
| |
| if chunksize is not None: |
| properties.chunksize = chunksize |
| |
| if compression_level is not None: |
| properties.compression_level = compression_level |
| |
| with nogil: |
| check_status(WriteFeather(deref(table.table), sink.get(), |
| properties)) |
| |
| |
| cdef class FeatherReader(_Weakrefable): |
| cdef: |
| shared_ptr[CFeatherReader] reader |
| |
| def __cinit__(self): |
| pass |
| |
| def open(self, source, c_bool use_memory_map=True): |
| cdef shared_ptr[CRandomAccessFile] reader |
| get_reader(source, use_memory_map, &reader) |
| |
| with nogil: |
| self.reader = GetResultValue(CFeatherReader.Open(reader)) |
| |
| @property |
| def version(self): |
| return self.reader.get().version() |
| |
| def read(self): |
| cdef shared_ptr[CTable] sp_table |
| with nogil: |
| check_status(self.reader.get() |
| .Read(&sp_table)) |
| |
| return pyarrow_wrap_table(sp_table) |
| |
| def read_indices(self, indices): |
| cdef: |
| shared_ptr[CTable] sp_table |
| vector[int] c_indices |
| |
| for index in indices: |
| c_indices.push_back(index) |
| with nogil: |
| check_status(self.reader.get() |
| .Read(c_indices, &sp_table)) |
| |
| return pyarrow_wrap_table(sp_table) |
| |
| def read_names(self, names): |
| cdef: |
| shared_ptr[CTable] sp_table |
| vector[c_string] c_names |
| |
| for name in names: |
| c_names.push_back(tobytes(name)) |
| with nogil: |
| check_status(self.reader.get() |
| .Read(c_names, &sp_table)) |
| |
| return pyarrow_wrap_table(sp_table) |