# 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 # cython: profile=False # distutils: language = c++ # cython: language_level=3 from cython.operator cimport dereference as deref from pyarrow.includes.common cimport * from pyarrow.includes.libarrow cimport * from pyarrow.includes.libarrow_feather cimport * from pyarrow.lib cimport (check_status, Table, _Weakrefable, get_writer, get_reader, pyarrow_wrap_table) from pyarrow.lib import tobytes 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, source, c_bool use_memory_map): 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)