######################################################################## # # License: BSD # Created: June 17, 2005 # Author: Francesc Alted - faltet@pytables.com # # $Id$ # ######################################################################## """Here is where Table and Row extension types live. Classes (type extensions): Table Row Functions: Misc variables: """ import math import os import platform import sys import numpy as np from time import time from .description import Col from .exceptions import HDF5ExtError from .conditions import call_on_recarr from .utilsextension import (get_nested_field, atom_from_hdf5_type, create_nested_type, hdf5_to_np_ext_type, create_nested_type, platform_byteorder, pttype_to_hdf5, pt_special_kinds, npext_prefixes_to_ptkinds, hdf5_class_to_string, H5T_STD_I64) from .utils import SizeType from .utilsextension cimport get_native_type, cstr_to_pystr # numpy functions & objects from .hdf5extension cimport Leaf from cpython cimport PyErr_Clear from libc.stdio cimport snprintf from libc.stdlib cimport malloc, free from libc.stdint cimport int32_t from libc.string cimport memcpy, strdup, strcmp, strlen from numpy cimport (import_array, ndarray, npy_intp, PyArray_GETITEM, PyArray_SETITEM, PyArray_BYTES, PyArray_DATA, PyArray_NDIM, PyArray_STRIDE) from .definitions cimport (hid_t, herr_t, hsize_t, haddr_t, htri_t, hbool_t, H5F_ACC_RDONLY, H5P_DEFAULT, H5D_CHUNKED, H5T_DIR_DEFAULT, H5F_SCOPE_LOCAL, H5F_SCOPE_GLOBAL, H5T_COMPOUND, H5Tget_order, H5Fflush, H5Dget_create_plist, H5T_ORDER_LE, H5D_layout_t, H5Dopen, H5Dclose, H5Dread, H5Dget_type, H5Dget_space, H5Pget_layout, H5Pget_chunk, H5Pclose, H5Sget_simple_extent_ndims, H5Sget_simple_extent_dims, H5Sclose, H5T_class_t, H5Tget_size, H5Tset_size, H5Tcreate, H5Tcopy, H5Tclose, H5Tget_nmembers, H5Tget_member_name, H5Tget_member_type, H5Tget_native_type, H5Tget_member_offset, H5Tinsert, H5Tget_class, H5Tget_super, H5Tget_offset, H5T_cset_t, H5T_CSET_ASCII, H5T_CSET_UTF8, H5ATTRset_attribute_string, H5ATTRset_attribute, get_len_of_range, get_order, set_order, is_complex, conv_float64_timeval32, truncate_dset, H5free_memory) from .lrucacheextension cimport ObjectCache, NumCache #----------------------------------------------------------------- # Optimized HDF5 API for PyTables cdef extern from "H5TB-opt.h" nogil: ctypedef struct chunk_iter_op: size_t itemsize size_t chunkshape haddr_t *addrs int fill_chunk_addrs(hid_t dataset_id, hsize_t nchunks, chunk_iter_op *chunk_op) int clean_chunk_addrs(chunk_iter_op *chunk_op) herr_t H5TBOmake_table( char *table_title, hid_t loc_id, char *dset_name, char *version, char *class_, hid_t mem_type_id, hsize_t nrecords, hsize_t chunk_size, hsize_t block_size, void *fill_data, int compress, char *complib, int shuffle, int fletcher32, hbool_t track_times, hbool_t blosc2_support, void *data ) herr_t H5TBOread_records( char* filename, hbool_t blosc2_support, chunk_iter_op chunk_op, hid_t dataset_id, hid_t mem_type_id, hsize_t start, hsize_t nrecords, void *data ) herr_t H5TBOread_elements( hid_t dataset_id, hid_t mem_type_id, hsize_t nrecords, void *coords, void *data ) herr_t H5TBOappend_records( hbool_t blosc2_support, hid_t dataset_id, hid_t mem_type_id, hsize_t start, hsize_t nrecords, void *data ) herr_t H5TBOwrite_records ( hbool_t blosc2_support, hid_t dataset_id, hid_t mem_type_id, hsize_t start, hsize_t nrecords, hsize_t step, void *data ) herr_t write_records_blosc2( hid_t dataset_id, hid_t mem_type_id, hsize_t start, hsize_t nrecords, const void *data ) herr_t H5TBOwrite_elements( hid_t dataset_id, hid_t mem_type_id, hsize_t nrecords, void *coords, void *data ) herr_t H5TBOdelete_records( char* filename, hbool_t blosc2_support, chunk_iter_op chunk_op, hid_t dataset_id, hid_t mem_type_id, hsize_t ntotal_records, size_t src_size, hsize_t start, hsize_t nrecords, hsize_t maxtuples ) #---------------------------------------------------------------------------- # Initialization code # The numpy API requires this function to be called before # using any numpy facilities in an extension module. import_array() #------------------------------------------------------------- # Private functions cdef get_nested_field_cache(recarray, fieldname, fieldcache): """Get the maybe nested field named `fieldname` from the `recarray`. The `fieldname` may be a simple field name or a nested field name with slah-separated components. It can also be an integer specifying the position of the field. """ try: field = fieldcache[fieldname] except KeyError: # Check whether fieldname is an integer and if so, get the field # straight from the recarray dictionary (it can't be anywhere else) if isinstance(fieldname, int): field = recarray[fieldname] else: field = get_nested_field(recarray, fieldname) fieldcache[fieldname] = field return field cdef join_path(object parent, object name): if parent == "": return name else: return parent + '/' + name # Public classes cdef class Table(Leaf): # instance variables cdef void *wbuf cdef chunk_iter_op chunk_op cdef hbool_t blosc2_support_read cdef hbool_t blosc2_support_write def _create_table(self, title, complib, obversion): cdef int offset cdef int ret cdef long buflen cdef hid_t oid cdef void *data cdef hsize_t nrows cdef bytes class_ cdef ndarray wdflts cdef void *fill_data cdef ndarray recarr cdef object name cdef bytes encoded_title, encoded_complib, encoded_obversion cdef char *ctitle = NULL cdef char *cobversion = NULL cdef bytes encoded_name cdef char fieldname[128] cdef int i cdef H5T_cset_t cset = H5T_CSET_ASCII encoded_title = title.encode('utf-8') encoded_complib = complib.encode('utf-8') encoded_obversion = obversion.encode('utf-8') encoded_name = self.name.encode('utf-8') # Get the C pointer ctitle = encoded_title cobversion = encoded_obversion # Compute the complete compound datatype based on the table description self.disk_type_id = create_nested_type(self.description, self.byteorder) #self.type_id = H5Tcopy(self.disk_type_id) # A H5Tcopy only is not enough, as we want the in-memory type to be # in the byteorder of the machine (sys.byteorder). self.type_id = create_nested_type(self.description, sys.byteorder) # The fill values area wdflts = self._v_wdflts if wdflts is None: fill_data = NULL else: fill_data = PyArray_DATA(wdflts) # test if there is data to be saved initially if self._v_recarray is not None: recarr = self._v_recarray data = PyArray_DATA(recarr) else: data = NULL # Decide whether Blosc2 optimized operations can be used. self.blosc2_support_write = ( (self.byteorder == sys.byteorder) and (self.filters.complib is not None) and (self.filters.complib.startswith("blosc2"))) # For reading, Windows does not support re-opening a file twice # in not read-only mode (for good reason), so we cannot use the # blosc2 opt self.blosc2_support_read = ( self.blosc2_support_write and ((platform.system().lower() != 'windows') or (self._v_file.mode == 'r'))) class_ = self._c_classid.encode('utf-8') cdef hsize_t blocksize = int(os.environ.get("PT_DEFAULT_B2_BLOCKSIZE", "0")) self.dataset_id = H5TBOmake_table(ctitle, self.parent_id, encoded_name, cobversion, class_, self.disk_type_id, self.nrows, self.chunkshape[0], blocksize, fill_data, self.filters.complevel, encoded_complib, self.filters.shuffle_bitshuffle, self.filters.fletcher32, self._want_track_times, self.blosc2_support_write, data) if self.dataset_id < 0: raise HDF5ExtError("Problems creating the table") if self._v_file.params['PYTABLES_SYS_ATTRS']: cset = H5T_CSET_UTF8 # Set the conforming table attributes # Attach the CLASS attribute ret = H5ATTRset_attribute_string(self.dataset_id, "CLASS", class_, len(class_), cset) if ret < 0: raise HDF5ExtError("Can't set attribute '%s' in table:\n %s." % ("CLASS", self.name)) # Attach the VERSION attribute ret = H5ATTRset_attribute_string(self.dataset_id, "VERSION", cobversion, len(encoded_obversion), cset) if ret < 0: raise HDF5ExtError("Can't set attribute '%s' in table:\n %s." % ("VERSION", self.name)) # Attach the TITLE attribute ret = H5ATTRset_attribute_string(self.dataset_id, "TITLE", ctitle, len(encoded_title), cset) if ret < 0: raise HDF5ExtError("Can't set attribute '%s' in table:\n %s." % ("TITLE", self.name)) # Attach the NROWS attribute nrows = self.nrows ret = H5ATTRset_attribute(self.dataset_id, "NROWS", H5T_STD_I64, 0, NULL, &nrows) if ret < 0: raise HDF5ExtError("Can't set attribute '%s' in table:\n %s." % ("NROWS", self.name)) # Attach the FIELD_N_NAME attributes # We write only the first level names for i, name in enumerate(self.description._v_names): snprintf(fieldname, 128, "FIELD_%d_NAME", i) encoded_name = name.encode('utf-8') ret = H5ATTRset_attribute_string(self.dataset_id, fieldname, encoded_name, len(encoded_name), cset) if ret < 0: raise HDF5ExtError("Can't set attribute '%s' in table:\n %s." % (fieldname, self.name)) # If created in PyTables, the table is always chunked self._chunked = True # Accessible from python # Initialize blosc2 struct for chunk addresses self.chunk_op = chunk_iter_op(self.description._v_itemsize, self.chunkshape[0], NULL) # Finally, return the object identifier. return self.dataset_id cdef get_nested_type(self, hid_t type_id, hid_t native_type_id, object colpath, object field_byteorders): """Open a nested type and return a nested dictionary as description.""" cdef hid_t member_type_id, native_member_type_id, member_offset cdef hsize_t nfields, i cdef hsize_t dims[1] cdef size_t itemsize cdef char *c_colname cdef H5T_class_t class_id cdef char c_byteorder2[11] # "irrelevant" fits easily here cdef char *sys_byteorder cdef object desc, colobj, colpath2, typeclassname, typeclass cdef object byteorder cdef str colname, byteorder2 offset = 0 desc = {} # Get the number of members nfields = H5Tget_nmembers(type_id) # Iterate through fields to get the correct order that elements may appear in # The object type can be stored not in order, so order based on the offset in the data position_order = [] for i in range(nfields): member_offset = H5Tget_member_offset(type_id, i) position_order.append((member_offset, i)) position_order.sort() # Iterate thru the members for pos, i in enumerate([x[1] for x in position_order]): # Get the member name c_colname = H5Tget_member_name(type_id, i) colname = cstr_to_pystr(c_colname) # Get the member type member_type_id = H5Tget_member_type(type_id, i) # Get the member offset member_offset = H5Tget_member_offset(type_id, i) # Get the HDF5 class class_id = H5Tget_class(member_type_id) if class_id == H5T_COMPOUND and not is_complex(member_type_id): colpath2 = join_path(colpath, colname) # Create the native data in-memory itemsize = H5Tget_size(member_type_id) native_member_type_id = H5Tcreate(H5T_COMPOUND, itemsize) desc[colname], itemsize = self.get_nested_type( member_type_id, native_member_type_id, colpath2, field_byteorders) desc[colname]["_v_pos"] = pos desc[colname]["_v_offset"] = member_offset else: # Get the member format and the corresponding Col object try: native_member_type_id = get_native_type(member_type_id) atom = atom_from_hdf5_type(native_member_type_id) colobj = Col.from_atom(atom, pos=pos, _offset=member_offset) itemsize = H5Tget_size(native_member_type_id) except TypeError, te: # Re-raise TypeError again with more info raise TypeError( ("table ``%s``, column ``%s``: %%s" % (self.name, colname)) % te.args[0]) desc[colname] = colobj # For time kinds, save the byteorder of the column # (useful for conversion of time datatypes later on) if colobj.kind == "time": colobj._byteorder = H5Tget_order(member_type_id) if colobj._byteorder == H5T_ORDER_LE: field_byteorders.append("little") else: field_byteorders.append("big") elif colobj.kind in ['int', 'uint', 'float', 'complex', 'enum']: # Keep track of the byteorder for this column get_order(member_type_id, c_byteorder2) byteorder2 = cstr_to_pystr(c_byteorder2) if byteorder2 in ["little", "big"]: field_byteorders.append(byteorder2) # Insert the native member H5Tinsert(native_type_id, c_colname, member_offset, native_member_type_id) # Update the offset offset = offset + itemsize # Release resources H5Tclose(native_member_type_id) H5Tclose(member_type_id) H5free_memory(c_colname) # set the byteorder and other things (just in top level) if colpath == "": # Compute a byteorder for the entire table if len(field_byteorders) > 0: field_byteorders = np.array(field_byteorders) # Cython doesn't interpret well the extended comparison # operators so this: field_byteorders == "little" doesn't work # as expected if np.all(field_byteorders.__eq__("little")): byteorder = "little" elif np.all(field_byteorders.__eq__("big")): byteorder = "big" else: # Yes! someone has done it! byteorder = "mixed" else: byteorder = "irrelevant" self.byteorder = byteorder return desc, offset def _get_info(self): """Get info from a table on disk.""" cdef hid_t space_id, plist cdef size_t type_size, size2 cdef hsize_t dims[1] # enough for unidimensional tables cdef hsize_t chunksize[1] cdef H5D_layout_t layout cdef bytes encoded_name # Open the dataset encoded_name = self.name.encode('utf-8') self.dataset_id = H5Dopen(self.parent_id, encoded_name, H5P_DEFAULT) if self.dataset_id < 0: raise HDF5ExtError("Non-existing node ``%s`` under ``%s``" % (self.name, self._v_parent._v_pathname)) # Get the datatype on disk self.disk_type_id = H5Dget_type(self.dataset_id) if H5Tget_class(self.disk_type_id) != H5T_COMPOUND: raise ValueError("Node ``%s`` is not a Table object" % (self._v_parent._v_leaves[self.name]._v_pathname)) # Get the number of rows space_id = H5Dget_space(self.dataset_id) H5Sget_simple_extent_dims(space_id, dims, NULL) self.nrows = SizeType(dims[0]) # Free resources H5Sclose(space_id) # Get the layout of the datatype plist = H5Dget_create_plist(self.dataset_id) layout = H5Pget_layout(plist) if layout == H5D_CHUNKED: self._chunked = 1 # Get the chunksize H5Pget_chunk(plist, 1, chunksize) else: self._chunked = 0 chunksize[0] = 0 H5Pclose(plist) # Get the type size type_size = H5Tget_size(self.disk_type_id) # Create the native data in-memory self.type_id = H5Tcreate(H5T_COMPOUND, type_size) # Fill-up the (nested) native type and description desc, offset = self.get_nested_type(self.disk_type_id, self.type_id, "", []) if desc == {}: raise HDF5ExtError("Problems getting desciption for table %s", self.name) if offset < type_size: # Trailing padding, set the itemsize to the correct type_size (see #765) desc['_v_itemsize'] = type_size # Initialize blosc2 struct for chunk addresses self.chunk_op = chunk_iter_op(type_size, chunksize[0], NULL) # Return the object ID and the description return (self.dataset_id, desc, SizeType(chunksize[0])) cdef _convert_time64_(self, ndarray nparr, hsize_t nrecords, int sense): """Converts a NumPy of Time64 elements between NumPy and HDF5 formats. NumPy to HDF5 conversion is performed when 'sense' is 0. Otherwise, HDF5 to NumPy conversion is performed. The conversion is done in place, i.e. 'nparr' is modified. """ cdef void *t64buf cdef long byteoffset cdef npy_intp bytestride, nelements byteoffset = 0 # NumPy objects doesn't have an offset bytestride = PyArray_STRIDE(nparr, 0) # supports multi-dimensional recarray # Compute the number of elements in the multidimensional cell nelements = nparr.size // len(nparr) t64buf = PyArray_DATA(nparr) conv_float64_timeval32( t64buf, byteoffset, bytestride, nrecords, nelements, sense) cpdef _convert_types(self, ndarray recarr, hsize_t nrecords, int sense): """Converts columns in 'recarr' between NumPy and HDF5 formats. NumPy to HDF5 conversion is performed when 'sense' is 0. Otherwise, HDF5 to NumPy conversion is performed. The conversion is done in place, i.e. 'recarr' is modified. """ # For reading, first swap the byteorder by hand # (this is not currently supported by HDF5) if sense == 1: for colpathname in self.colpathnames: if self.coltypes[colpathname] in ["time32", "time64"]: colobj = self.coldescrs[colpathname] if hasattr(colobj, "_byteorder"): if colobj._byteorder != platform_byteorder: column = get_nested_field(recarr, colpathname) # Do an *inplace* byteswapping column.byteswap(True) # This should be generalised to support other type conversions. for t64cname in self._time64colnames: column = get_nested_field(recarr, t64cname) self._convert_time64_(column, nrecords, sense) def _open_append(self, ndarray recarr): self._v_recarray = recarr # Get the pointer to the buffer data area self.wbuf = PyArray_DATA(recarr) def _append_records(self, hsize_t nrecords): cdef int ret cdef hsize_t nrows # Clean address cache self._clean_chunk_addrs() # Convert some NumPy types to HDF5 before storing. self._convert_types(self._v_recarray, nrecords, 0) nrows = self.nrows # release GIL (allow other threads to use the Python interpreter) with nogil: # Append the records: ret = H5TBOappend_records(self.blosc2_support_write, self.dataset_id, self.type_id, nrows, nrecords, self.wbuf) if ret < 0: raise HDF5ExtError("Problems appending the records.") self.nrows = self.nrows + nrecords def _close_append(self): cdef hsize_t nrows if self._v_file.params['PYTABLES_SYS_ATTRS']: # Update the NROWS attribute nrows = self.nrows if (H5ATTRset_attribute(self.dataset_id, "NROWS", H5T_STD_I64, 0, NULL, &nrows) < 0): raise HDF5ExtError("Problems setting the NROWS attribute.") # Set the caches to dirty (in fact, and for the append case, # it should be only the caches based on limits, but anyway) self._dirtycache = True self._clean_chunk_addrs() # Delete the reference to recarray as we doesn't need it anymore self._v_recarray = None def _update_records(self, hsize_t start, hsize_t stop, hsize_t step, ndarray recarr): cdef herr_t ret cdef void *rbuf cdef hsize_t nrecords, nrows # Get the pointer to the buffer data area rbuf = PyArray_DATA(recarr) # Compute the number of records to update nrecords = len(recarr) nrows = get_len_of_range(start, stop, step) if nrecords > nrows: nrecords = nrows # Convert some NumPy types to HDF5 before storing. self._convert_types(recarr, nrecords, 0) # Update the records: with nogil: ret = H5TBOwrite_records(self.blosc2_support_write and (step == 1), self.dataset_id, self.type_id, start, nrecords, step, rbuf) if ret < 0: raise HDF5ExtError("Problems updating the records.") # Set the caches to dirty self._dirtycache = True self._clean_chunk_addrs() def _update_elements(self, hsize_t nrecords, ndarray coords, ndarray recarr): cdef herr_t ret cdef void *rbuf cdef void *rcoords # Get the chunk of the coords that correspond to a buffer rcoords = PyArray_DATA(coords) # Get the pointer to the buffer data area rbuf = PyArray_DATA(recarr) # Convert some NumPy types to HDF5 before storing. self._convert_types(recarr, nrecords, 0) # Update the records: with nogil: ret = H5TBOwrite_elements(self.dataset_id, self.type_id, nrecords, rcoords, rbuf) if ret < 0: raise HDF5ExtError("Problems updating the records.") # Set the caches to dirty self._dirtycache = True self._clean_chunk_addrs() def _read_records(self, hsize_t start, hsize_t nrecords, ndarray recarr): cdef void *rbuf cdef int ret cdef bytes fname = self._v_file.filename.encode('utf8') cdef char* filename = fname if self.blosc2_support_read: # Grab the addresses for the blosc2 frames (HDF5 chunks) nchunks = math.ceil(self.nrows / self.chunkshape[0]) fill_chunk_addrs(self.dataset_id, nchunks, &self.chunk_op) # Correct the number of records to read, if needed if (start + nrecords) > self.nrows: nrecords = self.nrows - start # Get the pointer to the buffer data area rbuf = PyArray_DATA(recarr) # Read the records from disk with nogil: ret = H5TBOread_records(filename, self.blosc2_support_read, self.chunk_op, self.dataset_id, self.type_id, start, nrecords, rbuf) if ret < 0: raise HDF5ExtError("Problems reading records.") # Convert some HDF5 types to NumPy after reading. self._convert_types(recarr, nrecords, 1) return nrecords cdef hsize_t _read_chunk(self, hsize_t nchunk, ndarray iobuf, long cstart): cdef long nslot cdef hsize_t start, nrecords, chunkshape cdef int ret cdef void *rbuf cdef NumCache chunkcache cdef bytes fname = self._v_file.filename.encode('utf8') cdef char* filename = fname if self.blosc2_support_read: # Grab the addresses for the blosc2 frames (HDF5 chunks) nchunks = math.ceil(self.nrows / self.chunkshape[0]) fill_chunk_addrs(self.dataset_id, nchunks, &self.chunk_op) chunkcache = self._chunkcache chunkshape = chunkcache.slotsize # Correct the number of records to read, if needed start = nchunk*chunkshape nrecords = chunkshape if (start + nrecords) > self.nrows: nrecords = self.nrows - start rbuf = PyArray_BYTES(iobuf) + cstart * chunkcache.itemsize # Try to see if the chunk is in cache nslot = chunkcache.getslot_(nchunk) if nslot >= 0: chunkcache.getitem_(nslot, rbuf, 0) else: # Chunk is not in cache. Read it and put it in the LRU cache. with nogil: ret = H5TBOread_records(filename, self.blosc2_support_read, self.chunk_op, self.dataset_id, self.type_id, start, nrecords, rbuf) if ret < 0: raise HDF5ExtError("Problems reading chunk records.") nslot = chunkcache.setitem_(nchunk, rbuf, 0) return nrecords def _read_elements(self, ndarray coords, ndarray recarr): cdef long nrecords cdef void *rbuf cdef void *rbuf2 cdef int ret # Get the chunk of the coords that correspond to a buffer nrecords = coords.size # Get the pointer to the buffer data area rbuf = PyArray_DATA(recarr) # Get the pointer to the buffer coords area rbuf2 = PyArray_DATA(coords) with nogil: ret = H5TBOread_elements(self.dataset_id, self.type_id, nrecords, rbuf2, rbuf) if ret < 0: raise HDF5ExtError("Problems reading records.") # Convert some HDF5 types to NumPy after reading. self._convert_types(recarr, nrecords, 1) return nrecords def _remove_rows(self, hsize_t start, hsize_t stop, long step): cdef size_t rowsize cdef hsize_t nrecords=0, nrecords2 cdef hsize_t i cdef bytes fname = self._v_file.filename.encode('utf8') cdef char* filename = fname if step == 1: nrecords = stop - start rowsize = self.rowsize # Using self.disk_type_id should be faster (i.e. less conversions) if (H5TBOdelete_records(filename, self.blosc2_support_read, self.chunk_op, self.dataset_id, self.disk_type_id, self.nrows, rowsize, start, nrecords, self.nrowsinbuf) < 0): raise HDF5ExtError("Problems deleting records.") self.nrows = self.nrows - nrecords if self._v_file.params['PYTABLES_SYS_ATTRS']: # Attach the NROWS attribute nrecords2 = self.nrows H5ATTRset_attribute(self.dataset_id, "NROWS", H5T_STD_I64, 0, NULL, &nrecords2) # Set the caches to dirty self._dirtycache = True self._clean_chunk_addrs() elif step == -1: nrecords = self._remove_rows(stop+1, start+1, 1) elif step >= 1: # always want to go through the space backwards for i in range(stop - step, start - step, -step): nrecords += self._remove_rows(i, i+1, 1) elif step <= -1: # always want to go through the space backwards for i in range(start, stop, step): nrecords += self._remove_rows(i, i+1, 1) else: raise ValueError("step size may not be 0.") # Return the number of records removed return nrecords # Clean address cache def _clean_chunk_addrs(self): clean_chunk_addrs(&self.chunk_op) cdef class Row: """Table row iterator and field accessor. Instances of this class are used to fetch and set the values of individual table fields. It works very much like a dictionary, where keys are the pathnames or positions (extended slicing is supported) of the fields in the associated table in a specific row. This class provides an *iterator interface* so that you can use the same Row instance to access successive table rows one after the other. There are also some important methods that are useful for accessing, adding and modifying values in tables. .. rubric:: Row attributes .. attribute:: nrow The current row number. This property is useful for knowing which row is being dealt with in the middle of a loop or iterator. """ cdef npy_intp _stride cdef long _row, _unsaved_nrows, _mod_nrows cdef long long start, absstep cdef long long stop, step, nextelement, _nrow, stopb # has to be long long, not hsize_t, for negative step sizes cdef long long nrowsinbuf, nrows, nrowsread cdef long long chunksize, nchunksinbuf, totalchunks cdef long long startb, lenbuf cdef long long indexchunk cdef int bufcounter, counter cdef int exist_enum_cols cdef int _riterator, _rowsize, _write_to_seqcache cdef int wherecond, indexed cdef int ro_filemode, chunked cdef int _bufferinfo_done, sss_on cdef long long iterseq_max_elements cdef ndarray bufcoords, indexvalid, indexvalues, chunkmap cdef hsize_t *bufcoords_data cdef hsize_t *index_values_data cdef char *chunkmap_data cdef char *index_valid_data cdef object dtype cdef object iobuf, iobufcpy cdef object wrec, wreccpy cdef object wfields, rfields cdef object coords cdef object condfunc, condargs, condkwargs cdef object mod_elements, colenums cdef object rfieldscache, wfieldscache cdef object iterseq cdef object _table_file, _table_path cdef object modified_fields cdef object seqcache_key # The nrow() method has been converted into a property, which is handier property nrow: """The current row number. This property is useful for knowing which row is being dealt with in the middle of a loop or iterator. """ def __get__(self): return SizeType(self._nrow) property table: def __get__(self): self._table_file._check_open() return self._table_file._get_node(self._table_path) def __cinit__(self, table): cdef int nfields, i # Location-dependent information. self._table_file = table._v_file self._table_path = table._v_pathname self._unsaved_nrows = 0 self._mod_nrows = 0 self._row = 0 self._nrow = 0 # Useful in mod_append read iterators self._riterator = 0 self._bufferinfo_done = 0 # Some variables from table will be cached here if table._v_file.mode == 'r': self.ro_filemode = 1 else: self.ro_filemode = 0 self.chunked = table._chunked self.colenums = table._colenums self.exist_enum_cols = len(self.colenums) self.nrowsinbuf = table.nrowsinbuf self.chunksize = table.chunkshape[0] self.nchunksinbuf = self.nrowsinbuf // self.chunksize self.dtype = table._v_dtype self._new_buffer(table) self.mod_elements = None self.rfieldscache = {} self.wfieldscache = {} self.modified_fields = set() def _iter(self, start=0, stop=0, step=1, coords=None, chunkmap=None): """Return an iterator for traversiong the data in table.""" self._init_loop(start, stop, step, coords, chunkmap) return iter(self) def __iter__(self): """Iterator that traverses all the data in the Table""" return self cdef _new_buffer(self, table): """Create the recarrays for I/O buffering""" wdflts = table._v_wdflts if wdflts is None: self.wrec = np.zeros(1, dtype=self.dtype) # Defaults are zero else: self.wrec = table._v_wdflts.copy() self.wreccpy = self.wrec.copy() # A copy of the defaults # Build the wfields dictionary for faster access to columns self.wfields = {} for name in self.dtype.names: self.wfields[name] = self.wrec[name] # Get the read buffer for this instance (it is private, remember!) buff = self.iobuf = table._get_container(self.nrowsinbuf) # Build the rfields dictionary for faster access to columns # This is quite fast, as it only takes around 5 us per column # in my laptop (Pentium 4 @ 2 GHz). # F. Alted 2006-08-18 self.rfields = {} for i, name in enumerate(self.dtype.names): self.rfields[i] = buff[name] self.rfields[name] = buff[name] # Get the stride of these buffers self._stride = PyArray_STRIDE(buff, 0) # The rowsize self._rowsize = self.dtype.itemsize self.nrows = table.nrows # This value may change cdef _init_loop(self, long long start, long long stop, long long step, object coords, object chunkmap): """Initialization for the __iter__ iterator""" cdef Table table = self.table self._riterator = 1 # We are inside a read iterator self.start = start self.stop = stop self.step = step self.coords = coords self.startb = 0 if step > 0: self._row = -1 # a sentinel self.nrowsread = start elif step < 0: self._row = 0 self.nrowsread = 0 self.nextelement = start self._nrow = start - self.step self.wherecond = 0 self.indexed = 0 self.nrows = table.nrows # Update the row counter if table.blosc2_support_read: # Grab the addresses for the blosc2 frames (HDF5 chunks) nchunks = math.ceil(self.nrows / self.table.chunkshape[0]) fill_chunk_addrs(table.dataset_id, nchunks, &table.chunk_op) if coords is not None and 0 < step: self.nrowsread = start self.nextelement = start self.stop = min(stop, len(coords)) self.absstep = abs(step) return elif coords is not None and 0 > step: #self.nrowsread = 0 #self.nextelement = start #self.stop = min(stop, len(coords)) #self.stop = max(stop, start - len(coords)) self.absstep = abs(step) return if table._where_condition: self.wherecond = 1 #self.condkwargs = {'ex_uses_vml': True} self.condfunc, self.condargs, self.condkwargs = table._where_condition table._where_condition = None if table._use_index: # Indexing code depends on this condition (see #319) assert self.nrowsinbuf % self.chunksize == 0 self.indexed = 1 # Compute totalchunks here because self.nrows can change during the # life of a Row instance. self.totalchunks = self.nrows // self.chunksize if self.nrows % self.chunksize: self.totalchunks = self.totalchunks + 1 self.nrowsread = 0 self.nextelement = 0 self.chunkmap = chunkmap self.chunkmap_data = PyArray_BYTES(self.chunkmap) table._use_index = False self.lenbuf = self.nrowsinbuf # Check if we have limitations on start, stop, step self.sss_on = (self.start > 0 or self.stop < self.nrows or self.step > 1) self.seqcache_key = table._seqcache_key table._seqcache_key = None if self.seqcache_key is not None: self._write_to_seqcache = 1 self.iterseq_max_elements = table._v_file.params['ITERSEQ_MAX_ELEMENTS'] self.iterseq = [] # all the row indexes, unless it would be longer than ITERSEQ_MAX_ELEMENTS else: self._write_to_seqcache = 0 self.iterseq = None def __next__(self): """next() method for __iter__() that is called on each iteration""" if not self._riterator: # The iterator is already exhausted! raise StopIteration if self.indexed: return self.__next__indexed() elif self.coords is not None: return self.__next__coords() elif self.wherecond: return self.__next__inkernel() else: return self.__next__general() cdef __next__indexed(self): """The version of next() for indexed columns and a chunkmap.""" cdef long recout, j, cs, vlen, rowsize cdef long long nchunksread cdef object tmp_range cdef Table table cdef ndarray iobuf cdef void *IObufData cdef long nslot cdef object seq cdef object seqcache assert self.nrowsinbuf >= self.chunksize while self.nextelement < self.stop: if self.nextelement >= self.nrowsread: # Skip until there is interesting information while self.start > self.nrowsread + self.nrowsinbuf: self.nrowsread = self.nrowsread + self.nrowsinbuf self.nextelement = self.nextelement + self.nrowsinbuf table = self.table iobuf = self.iobuf j = 0; recout = 0; cs = self.chunksize nchunksread = self.nrowsread // cs tmp_range = np.arange(0, cs, dtype='int64') self.bufcoords = np.empty(self.nrowsinbuf, dtype='int64') # Fetch valid chunks until the I/O buffer is full while nchunksread < self.totalchunks: if self.chunkmap_data[nchunksread]: self.bufcoords[j*cs:(j+1)*cs] = tmp_range + self.nrowsread # Not optimized read # recout = recout + table._read_records( # nchunksread*cs, cs, iobuf[j*cs:]) # # Optimized read through the use of a chunk cache. This cache has # more or less the same speed than the integrated HDF5 chunk # cache, but using the PyTables one has the advantage that the # user can easily change this parameter. recout = recout + table._read_chunk(nchunksread, iobuf, j*cs) j = j + 1 self.nrowsread = (nchunksread+1)*cs if self.nrowsread > self.stop: self.nrowsread = self.stop break elif j == self.nchunksinbuf: break nchunksread = nchunksread + 1 # Evaluate the condition on this table fragment. iobuf = iobuf[:recout] if len(iobuf) > 0: self.table._convert_types(iobuf, len(iobuf), 1) self.indexvalid = call_on_recarr( self.condfunc, self.condargs, iobuf, **self.condkwargs) self.index_valid_data = PyArray_BYTES(self.indexvalid) # Get the valid coordinates self.indexvalues = self.bufcoords[:recout][self.indexvalid] self.index_values_data = PyArray_DATA(self.indexvalues) self.lenbuf = self.indexvalues.size # Place the valid results at the beginning of the buffer iobuf[:self.lenbuf] = iobuf[self.indexvalid] # Initialize the internal buffer row counter self._row = -1 if self._write_to_seqcache: # Feed the indexvalues into the seqcache seqcache = self.iterseq if self.lenbuf + len(seqcache) < self.iterseq_max_elements: seqcache.extend(self.indexvalues) else: self.iterseq = None self._write_to_seqcache = 0 self._row = self._row + 1 # Check whether we have read all the rows in buf if self._row == self.lenbuf: self.nextelement = self.nrowsread # Make _row to point to the last valid entry in buffer # (this is useful for accessing the last row after an iterator loop) self._row = self._row - 1 continue self._nrow = self.index_values_data[self._row] # Check additional conditions on start, stop, step params if self.sss_on: if (self._nrow < self.start or self._nrow >= self.stop): self.nextelement = self.nextelement + 1 continue if (self.step > 1 and ((self._nrow - self.start) % self.step > 0)): self.nextelement = self.nextelement + 1 continue # Return this row self.nextelement = self._nrow + 1 return self else: # All the elements have been read for this mode self._finish_riterator() cdef __next__coords(self): """The version of next() for user-required coordinates""" cdef int recout cdef long long lenbuf, nextelement cdef object tmp if 0 < self.step: while self.nextelement < self.stop: if self.nextelement >= self.nrowsread: # Correction for avoiding reading past self.stop if self.nrowsread+self.nrowsinbuf > self.stop: lenbuf = self.stop-self.nrowsread else: lenbuf = self.nrowsinbuf tmp = self.coords[self.nrowsread:self.nrowsread+lenbuf:self.step] # We have to get a contiguous buffer, so numpy.array is the way to go self.bufcoords = np.array(tmp, dtype="uint64") self._row = -1 if self.bufcoords.size > 0: recout = self.table._read_elements(self.bufcoords, self.iobuf) else: recout = 0 self.bufcoords_data = PyArray_DATA(self.bufcoords) self.nrowsread = self.nrowsread + lenbuf if recout == 0: # no items were read, skip out continue self._row = self._row + 1 self._nrow = self.bufcoords_data[self._row] self.nextelement = self.nextelement + self.absstep return self else: # All the elements have been read for this mode self._finish_riterator() elif 0 > self.step: #print("self.nextelement = ", self.nextelement, self.start, self.nrowsread, self.nextelement < self.start - self.nrowsread + 1) while self.nextelement > self.stop: if self.nextelement < self.start - ( self.nrowsread) + 1: if 0 > self.nextelement - ( self.nrowsinbuf) + 1: tmp = self.coords[0:self.nextelement + 1] else: tmp = self.coords[self.nextelement - ( self.nrowsinbuf) + 1:self.nextelement + 1] self.bufcoords = np.array(tmp, dtype="uint64") recout = self.table._read_elements(self.bufcoords, self.iobuf) self.bufcoords_data = PyArray_DATA(self.bufcoords) self.nrowsread = self.nrowsread + self.nrowsinbuf self._row = len(self.bufcoords) - 1 else: self._row = (self._row + self.step) % len(self.bufcoords) self._nrow = self.nextelement - self.step self.nextelement = self.nextelement + self.step # Return this value return self else: # All the elements have been read for this mode self._finish_riterator() else: self._finish_riterator() cdef __next__inkernel(self): """The version of next() in case of in-kernel conditions""" cdef hsize_t recout, correct cdef object numexpr_locals, colvar, col self.nextelement = self._nrow + self.step while self.nextelement < self.stop: if self.nextelement >= self.nrowsread: # Skip until there is interesting information while self.nextelement >= self.nrowsread + self.nrowsinbuf: self.nrowsread = self.nrowsread + self.nrowsinbuf # Compute the end for this iteration self.stopb = self.stop - self.nrowsread if self.stopb > self.nrowsinbuf: self.stopb = self.nrowsinbuf self._row = self.startb - self.step # Read a chunk recout = self.table._read_records(self.nextelement, self.nrowsinbuf, self.iobuf) self.nrowsread = self.nrowsread + recout self.indexchunk = -self.step # Evaluate the condition on this table fragment. self.indexvalid = call_on_recarr( self.condfunc, self.condargs, self.iobuf[:recout], **self.condkwargs) self.index_valid_data = PyArray_BYTES(self.indexvalid) # Is there any interesting information in this buffer? if not np.any(self.indexvalid): # No, so take the next one if self.step >= self.nrowsinbuf: self.nextelement = self.nextelement + self.step else: self.nextelement = self.nextelement + self.nrowsinbuf # Correction for step size > 1 if self.step > 1: correct = (self.nextelement - self.start) % self.step self.nextelement = self.nextelement - correct continue self._row = self._row + self.step self._nrow = self.nextelement if self._row + self.step >= self.stopb: # Compute the start row for the next buffer self.startb = 0 self.nextelement = self._nrow + self.step # Return only if this value is interesting self.indexchunk = self.indexchunk + self.step if self.index_valid_data[self.indexchunk]: return self else: self._finish_riterator() cdef __next__general(self): """The version of next() for the general cases""" cdef int recout if 0 < self.step: self.nextelement = self._nrow + self.step while self.nextelement < self.stop: if self.nextelement >= self.nrowsread: # Skip until there is interesting information while self.nextelement >= self.nrowsread + self.nrowsinbuf: self.nrowsread = self.nrowsread + self.nrowsinbuf # Compute the end for this iteration self.stopb = self.stop - self.nrowsread if self.stopb > self.nrowsinbuf: self.stopb = self.nrowsinbuf self._row = self.startb - self.step # Read a chunk recout = self.table._read_records(self.nrowsread, self.nrowsinbuf, self.iobuf) self.nrowsread = self.nrowsread + recout self._row = self._row + self.step self._nrow = self.nextelement if self._row + self.step >= self.stopb: # Compute the start row for the next buffer self.startb = (self._row + self.step) % self.nrowsinbuf self.nextelement = self._nrow + self.step # Return this value return self else: self._finish_riterator() elif 0 > self.step: self.stopb = -1 while self.nextelement - 1 > self.stop: if self.nextelement < self.start - self.nrowsread + 1: # Read a chunk recout = self.table._read_records(self.nextelement - self.nrowsinbuf + 1, self.nrowsinbuf, self.iobuf) self.nrowsread = self.nrowsread + self.nrowsinbuf self._row = self.nrowsinbuf - 1 else: self._row = (self._row + self.step) % self.nrowsinbuf self._nrow = self.nextelement - self.step self.nextelement = self.nextelement + self.step # Return this value return self else: self._finish_riterator() cdef _finish_riterator(self): """Clean-up things after iterator has been done""" cdef ObjectCache seqcache cdef Table table = self.table self.rfieldscache = {} # empty rfields cache self.wfieldscache = {} # empty wfields cache # Make a copy of the last read row in the private record # (this is useful for accessing the last row after an iterator loop) if self._row >= 0: self.wrec[:] = self.iobuf[self._row] if self._write_to_seqcache: seqcache = self.table._seqcache # Guessing iterseq size: Each element in self.iterseq should take at least 8 bytes seqcache.setitem_(self.seqcache_key, self.iterseq, len(self.iterseq) * 8) self._riterator = 0 # out of iterator self.iterseq = None # empty seqcache-related things self.seqcache_key = None if self._mod_nrows > 0: # Check if there is some modified row self._flush_mod_rows() # Flush any possible modified row self.modified_fields = set() # Empty the set of modified fields raise StopIteration # end of iteration def _fill_col(self, result, start, stop, step, field): """Read a field from a table on disk and put the result in result""" cdef hsize_t startr, istartb cdef long long istart, inrowsinbuf, inextelement cdef long long stopr, istopb, i, j, inrowsread cdef long long istop, istep cdef object fields # We can't reuse existing buffers in this context self._init_loop(start, stop, step, None, None) istart, istop, istep = self.start, self.stop, self.step inrowsinbuf, inextelement, inrowsread = self.nrowsinbuf, istart, istart istartb, startr = self.startb, 0 i = istart if 0 < istep: while i < istop: if (inextelement >= inrowsread + inrowsinbuf): inrowsread = inrowsread + inrowsinbuf i = i + inrowsinbuf continue # Compute the end for this iteration istopb = istop - inrowsread if istopb > inrowsinbuf: istopb = inrowsinbuf stopr = startr + ((istopb - istartb - 1) // istep) + 1 # Read a chunk inrowsread = inrowsread + self.table._read_records(i, inrowsinbuf, self.iobuf) # Assign the correct part to result fields = self.iobuf if field: fields = get_nested_field(fields, field) result[startr:stopr] = fields[istartb:istopb:istep] # Compute some indexes for the next iteration startr = stopr j = istartb + ((istopb - istartb - 1) // istep) * istep istartb = (j+istep) % inrowsinbuf inextelement = inextelement + istep i = i + inrowsinbuf elif istep < 0: inrowsinbuf = self.nrowsinbuf #istartb = self.startb istartb = self.nrowsinbuf - 1 #istopb = self.stopb - 1 istopb = -1 startr = 0 i = istart inextelement = istart inrowsread = 0 while i-1 > istop: #if (inextelement <= inrowsread + inrowsinbuf): if (inextelement < i - inrowsinbuf): inrowsread = inrowsread + inrowsinbuf i = i - inrowsinbuf continue # Compute the end for this iteration # (we know we are going backward so try to keep indices positive) stopr = startr + (1 - istopb + istartb) // (-istep) # Read a chunk inrowsread = inrowsread + self.table._read_records(i - inrowsinbuf + 1, inrowsinbuf, self.iobuf) # Assign the correct part to result fields = self.iobuf if field: fields = get_nested_field(fields, field) if istopb >= 0: result[startr:stopr] = fields[istartb:istopb:istep] else: result[startr:stopr] = fields[istartb::istep] # Compute some indexes for the next iteration startr = stopr istartb = (i - istartb)%inrowsinbuf inextelement = inextelement + istep i = i - inrowsinbuf self._riterator = 0 # out of iterator return def append(self): """Add a new row of data to the end of the dataset. Once you have filled the proper fields for the current row, calling this method actually appends the new data to the *output buffer* (which will eventually be dumped to disk). If you have not set the value of a field, the default value of the column will be used. .. warning:: After completion of the loop in which :meth:`Row.append` has been called, it is always convenient to make a call to :meth:`Table.flush` in order to avoid losing the last rows that may still remain in internal buffers. Examples -------- :: row = table.row for i in xrange(nrows): row['col1'] = i-1 row['col2'] = 'a' row['col3'] = -1.0 row.append() table.flush() """ cdef ndarray iobuf, wrec, wreccpy if self.ro_filemode: raise IOError("Attempt to write over a file opened in read-only mode") if not self.chunked: raise HDF5ExtError("You cannot append rows to a non-chunked table.", h5tb=False) if self._riterator: raise NotImplementedError("You cannot append rows when in middle of a table iterator. If what you want is to update records, use Row.update() instead.") # Commit the private record into the write buffer # self.iobuf[self._unsaved_nrows] = self.wrec # The next is faster iobuf = self.iobuf; wrec = self.wrec memcpy(PyArray_BYTES(iobuf) + self._unsaved_nrows * self._stride, PyArray_BYTES(wrec), self._rowsize) # Restore the defaults for the private record # self.wrec[:] = self.wreccpy # The next is faster wreccpy = self.wreccpy memcpy(PyArray_BYTES(wrec), PyArray_BYTES(wreccpy), self._rowsize) self._unsaved_nrows = self._unsaved_nrows + 1 # When the buffer is full, flush it if self._unsaved_nrows == self.nrowsinbuf: self._flush_buffered_rows() def _flush_buffered_rows(self): if self._unsaved_nrows > 0: self.table._save_buffered_rows(self.iobuf, self._unsaved_nrows) # Reset the buffer unsaved counter self._unsaved_nrows = 0 def _get_unsaved_nrows(self): return self._unsaved_nrows def update(self): """Change the data of the current row in the dataset. This method allows you to modify values in a table when you are in the middle of a table iterator like :meth:`Table.iterrows` or :meth:`Table.where`. Once you have filled the proper fields for the current row, calling this method actually changes data in the *output buffer* (which will eventually be dumped to disk). If you have not set the value of a field, its original value will be used. .. warning:: After completion of the loop in which :meth:`Row.update` has been called, it is always convenient to make a call to :meth:`Table.flush` in order to avoid losing changed rows that may still remain in internal buffers. Examples -------- :: for row in table.iterrows(step=10): row['col1'] = row.nrow row['col2'] = 'b' row['col3'] = 0.0 row.update() table.flush() which modifies every tenth row in table. Or:: for row in table.where('col1 > 3'): row['col1'] = row.nrow row['col2'] = 'b' row['col3'] = 0.0 row.update() table.flush() which just updates the rows with values bigger than 3 in the first column. """ cdef ndarray iobufcpy, iobuf if self.ro_filemode: raise IOError("Attempt to write over a file opened in read-only mode") if not self._riterator: raise NotImplementedError("You are only allowed to update rows through the Row.update() method if you are in the middle of a table iterator.") if self.mod_elements is None: # Initialize an array for keeping the modified elements # (just in case Row.update() would be used) self.mod_elements = np.empty(shape=self.nrowsinbuf, dtype=SizeType) # We need a different copy for self.iobuf here self.iobufcpy = self.iobuf.copy() # Add this row to the list of elements to be modified self.mod_elements[self._mod_nrows] = self._nrow # Copy the current buffer row in input to the output buffer # self.iobufcpy[self._mod_nrows] = self.iobuf[self._row] # The next is faster iobufcpy = self.iobufcpy; iobuf = self.iobuf memcpy(PyArray_BYTES(iobufcpy) + self._mod_nrows * self._stride, PyArray_BYTES(iobuf) + self._row * self._stride, self._rowsize) # Increase the modified buffer count by one self._mod_nrows = self._mod_nrows + 1 # No point writing seqcache -- Table.flush will invalidate it # since we no longer know whether this row will meet _where_condition self._write_to_seqcache = 0 # When the buffer is full, flush it if self._mod_nrows == self.nrowsinbuf: self._flush_mod_rows() def _flush_mod_rows(self): """Flush any possible modified row using Row.update()""" table = self.table # Save the records on disk table._update_elements(self._mod_nrows, self.mod_elements, self.iobufcpy) # Reset the counter of modified rows to 0 self._mod_nrows = 0 # Mark the modified fields' indexes as dirty. table._mark_columns_as_dirty(self.modified_fields) def __contains__(self, item): """__contains__(item) A true value is returned if item is found in current row, false otherwise. """ return item in self.fetch_all_fields() # This method is twice as faster than __getattr__ because there is # not a lookup in the local dictionary def __getitem__(self, key): """__getitem__(key) Get the row field specified by the `key`. The key can be a string (the name of the field), an integer (the position of the field) or a slice (the range of field positions). When key is a slice, the returned value is a *tuple* containing the values of the specified fields. Examples -------- :: res = [row['var3'] for row in table.where('var2 < 20')] which selects the var3 field for all the rows that fulfil the condition. Or:: res = [row[4] for row in table if row[1] < 20] which selects the field in the *4th* position for all the rows that fulfil the condition. Or:: res = [row[:] for row in table if row['var2'] < 20] which selects the all the fields (in the form of a *tuple*) for all the rows that fulfil the condition. Or:: res = [row[1::2] for row in table.iterrows(2, 3000, 3)] which selects all the fields in even positions (in the form of a *tuple*) for all the rows in the slice [2:3000:3]. """ cdef long offset cdef ndarray field cdef object row, fields, fieldscache if self._riterator: # If in the middle of an iterator loop, the user probably wants to # access the read buffer fieldscache = self.rfieldscache; fields = self.rfields offset = self._row else: # We are not in an iterator loop, so the user probably wants to access # the write buffer fieldscache = self.wfieldscache; fields = self.wfields offset = 0 try: # Check whether this object is in the cache dictionary field = fieldscache[key] except (KeyError, TypeError): try: # Try to get it from fields (str or int keys) field = get_nested_field_cache(fields, key, fieldscache) except TypeError: # No luck yet. Still, the key can be a slice. # Fetch the complete row and convert it into a tuple if self._riterator: row = self.iobuf[self._row].copy().item() else: row = self.wrec[0].copy().item() # Try with __getitem__() return row[key] if PyArray_NDIM(field) == 1: # For an scalar it is not needed a copy (immutable object) return PyArray_GETITEM(field, PyArray_BYTES(field) + offset * self._stride) else: # Do a copy of the array, so that it can be overwritten by the user # without damaging the internal self.rfields buffer return field[offset].copy() # This is slightly faster (around 3%) than __setattr__ def __setitem__(self, object key, object value): """__setitem__(key, value) Set the key row field to the specified value. Differently from its __getitem__() counterpart, in this case key can only be a string (the name of the field). The changes done via __setitem__() will not take effect on the data on disk until any of the :meth:`Row.append` or :meth:`Row.update` methods are called. Examples -------- :: for row in table.iterrows(step=10): row['col1'] = row.nrow row['col2'] = 'b' row['col3'] = 0.0 row.update() table.flush() which modifies every tenth row in the table. """ cdef int ret cdef long offset cdef ndarray field cdef object fields, fieldscache if self.ro_filemode: raise IOError("attempt to write over a file opened in read-only mode") if self._riterator: # If in the middle of an iterator loop, or *after*, the user # probably wants to access the read buffer fieldscache = self.rfieldscache; fields = self.rfields offset = self._row else: # We are not in an iterator loop, so the user probably wants to access # the write buffer fieldscache = self.wfieldscache; fields = self.wfields offset = 0 # Check validity of enumerated value. if self.exist_enum_cols: if key in self.colenums: enum = self.colenums[key] for cenval in np.asarray(value).flat: enum(cenval) # raises ``ValueError`` on invalid values # Get the field to be modified field = get_nested_field_cache(fields, key, fieldscache) if key not in self.modified_fields: self.modified_fields.add(key) # Finally, try to set it to the value try: # Optimization for scalar values. This can optimize the writes # between a 10% and 100%, depending on the number of columns modified if PyArray_NDIM(field) == 1: ret = PyArray_SETITEM(field, PyArray_BYTES(field) + offset * self._stride, value) if ret < 0: PyErr_Clear() raise TypeError ##### End of optimization for scalar values else: field[offset] = value except TypeError: raise TypeError("invalid type (%s) for column ``%s``" % (type(value), key)) def fetch_all_fields(self): """Retrieve all the fields in the current row. Contrarily to row[:] (see :ref:`RowSpecialMethods`), this returns row data as a NumPy void scalar. For instance:: [row.fetch_all_fields() for row in table.where('col1 < 3')] will select all the rows that fulfill the given condition as a list of NumPy records. """ # We need to do a cast for recognizing negative row numbers! if self._nrow < 0: return ("Warning: Row iterator has not been initialized for table:\n" " %s\n" " You will normally want to use this method in iterator " "contexts." % self.table) # Always return a copy of the row so that new data that is written # in self.iobuf doesn't overwrite the original returned data. return self.iobuf[self._row].copy() def __str__(self): """Represent the record as an string""" # We need to do a cast for recognizing negative row numbers! if self._nrow < 0: return ("Warning: Row iterator has not been initialized for table:\n" " %s\n" " You will normally want to use this object in iterator " "contexts." % self.table) tablepathname = self.table._v_pathname classname = self.__class__.__name__ return "%s.row (%s), pointing to row #%d" % (tablepathname, classname, self._nrow) def __repr__(self): """Represent the record as an string""" return str(self) ## Local Variables: ## mode: python ## py-indent-offset: 2 ## tab-width: 2 ## fill-column: 78 ## End: