我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用django.utils.six.memoryview()。
def fromfile(file_h): """ Given a string file name, returns a GEOSGeometry. The file may contain WKB, WKT, or HEX. """ # If given a file name, get a real handle. if isinstance(file_h, six.string_types): with open(file_h, 'rb') as file_h: buf = file_h.read() else: buf = file_h.read() # If we get WKB need to wrap in memoryview(), so run through regexes. if isinstance(buf, bytes): try: decoded = buf.decode() if wkt_regex.match(decoded) or hex_regex.match(decoded): return GEOSGeometry(decoded) except UnicodeDecodeError: pass else: return GEOSGeometry(buf) return GEOSGeometry(six.memoryview(buf))
def __set__(self, obj, value): """ This accessor sets the proxied geometry with the geometry class specified during initialization. Values of None, HEXEWKB, or WKT may be used to set the geometry as well. """ # The OGC Geometry type of the field. gtype = self._field.geom_type # The geometry type must match that of the field -- unless the # general GeometryField is used. if isinstance(value, self._klass) and (str(value.geom_type).upper() == gtype or gtype == 'GEOMETRY'): # Assigning the SRID to the geometry. if value.srid is None: value.srid = self._field.srid elif value is None or isinstance(value, six.string_types + (six.memoryview,)): # Set with None, WKT, HEX, or WKB pass else: raise TypeError('Cannot set %s GeometryProxy (%s) with value of type: %s' % ( obj.__class__.__name__, gtype, type(value))) # Setting the objects dictionary with the value, and returning. obj.__dict__[self._field.attname] = value return value
def __set__(self, obj, value): """ This accessor sets the proxied geometry or raster with the corresponding class specified during initialization. To set geometries, values of None, HEXEWKB, or WKT may be used. To set rasters, JSON or dict values may be used. """ # The geographic type of the field. gtype = self._field.geom_type if gtype == 'RASTER' and (value is None or isinstance(value, six.string_types + (dict, self._klass))): # For raster fields, assure input is None or a string, dict, or # raster instance. pass elif isinstance(value, self._klass) and (str(value.geom_type).upper() == gtype or gtype == 'GEOMETRY'): # The geometry type must match that of the field -- unless the # general GeometryField is used. if value.srid is None: # Assigning the field SRID if the geometry has no SRID. value.srid = self._field.srid elif value is None or isinstance(value, six.string_types + (six.memoryview,)): # Set geometries with None, WKT, HEX, or WKB pass else: raise TypeError('Cannot set %s SpatialProxy (%s) with value of type: %s' % ( obj.__class__.__name__, gtype, type(value))) # Setting the objects dictionary with the value, and returning. obj.__dict__[self._field.attname] = value return value
def wkb(self): "Returns the WKB representation of the Geometry." if sys.byteorder == 'little': byteorder = 1 # wkbNDR (from ogr_core.h) else: byteorder = 0 # wkbXDR sz = self.wkb_size # Creating the unsigned character buffer, and passing it in by reference. buf = (c_ubyte * sz)() capi.to_wkb(self.ptr, byteorder, byref(buf)) # Returning a buffer of the string at the pointer. return six.memoryview(string_at(buf, sz))
def read(self, wkb): "Returns a _pointer_ to C GEOS Geometry object from the given WKB." if isinstance(wkb, six.memoryview): wkb_s = bytes(wkb) return wkb_reader_read(self.ptr, wkb_s, len(wkb_s)) elif isinstance(wkb, (bytes, six.string_types)): return wkb_reader_read_hex(self.ptr, wkb, len(wkb)) else: raise TypeError # ### WKB/WKT Writer Classes ###
def write(self, geom): "Returns the WKB representation of the given geometry." return six.memoryview(wkb_writer_write(self.ptr, geom.ptr, byref(c_size_t())))
def quote_value(self, value): # The backend "mostly works" without this function and there are use # cases for compiling Python without the sqlite3 libraries (e.g. # security hardening). import sqlite3 try: value = sqlite3.adapt(value) except sqlite3.ProgrammingError: pass # Manual emulation of SQLite parameter quoting if isinstance(value, type(True)): return str(int(value)) elif isinstance(value, (Decimal, float)): return str(value) elif isinstance(value, six.integer_types): return str(value) elif isinstance(value, six.string_types): return "'%s'" % six.text_type(value).replace("\'", "\'\'") elif value is None: return "NULL" elif isinstance(value, (bytes, bytearray, six.memoryview)): # Bytes are only allowed for BLOB fields, encoded as string # literals containing hexadecimal data and preceded by a single "X" # character: # value = b'\x01\x02' => value_hex = b'0102' => return X'0102' value = bytes(value) hex_encoder = codecs.getencoder('hex_codec') value_hex, _length = hex_encoder(value) # Use 'ascii' encoding for b'01' => '01', no need to use force_text here. return "X'%s'" % value_hex.decode('ascii') else: raise ValueError("Cannot quote parameter value %r of type %s" % (value, type(value)))
def to_python(self, value): # If it's a string, it should be base64-encoded data if isinstance(value, six.text_type): return six.memoryview(b64decode(force_bytes(value))) return value
def __set__(self, instance, value): """ This accessor sets the proxied geometry or raster with the corresponding class specified during initialization. To set geometries, values of None, HEXEWKB, or WKT may be used. To set rasters, JSON or dict values may be used. """ # The geographic type of the field. gtype = self._field.geom_type if gtype == 'RASTER' and (value is None or isinstance(value, six.string_types + (dict, self._klass))): # For raster fields, assure input is None or a string, dict, or # raster instance. pass elif isinstance(value, self._klass) and (str(value.geom_type).upper() == gtype or gtype == 'GEOMETRY'): # The geometry type must match that of the field -- unless the # general GeometryField is used. if value.srid is None: # Assigning the field SRID if the geometry has no SRID. value.srid = self._field.srid elif value is None or isinstance(value, six.string_types + (six.memoryview,)): # Set geometries with None, WKT, HEX, or WKB pass else: raise TypeError('Cannot set %s SpatialProxy (%s) with value of type: %s' % ( instance.__class__.__name__, gtype, type(value))) # Setting the objects dictionary with the value, and returning. instance.__dict__[self._field.attname] = value return value
def write(self, geom): "Returns the WKB representation of the given geometry." from django.contrib.gis.geos import Polygon geom = self._handle_empty_point(geom) wkb = wkb_writer_write(self.ptr, geom.ptr, byref(c_size_t())) if isinstance(geom, Polygon) and geom.empty: # Fix GEOS output for empty polygon. # See https://trac.osgeo.org/geos/ticket/680. wkb = wkb[:-8] + b'\0' * 4 return six.memoryview(wkb)
def __setstate__(self, state): # Instantiating from the tuple state that was pickled. wkb, srid = state ptr = wkb_r().read(six.memoryview(wkb)) if not ptr: raise GEOSException('Invalid Geometry loaded from pickled state.') self.ptr = ptr self._post_init(srid) # Comparison operators
