Python struct.struct_pack函数代码示例

 def setQuestion(self, qname, qtype=QTYPE_A, qclass=QCLASS_IN):
     for label in qname.split('.'):
         label = str(label)
         l = len(label)
         self.buf += struct_pack('b', l)
         self.buf += struct_pack(str(l)+'s', label)
     self.buf += '\0'
     self.buf += self._pack16bit(qtype) 
     self.buf += self._pack16bit(qclass)

	def tick(self,sample,sample2=None):
		if (sample2 == None):
			s1 = int(self.sampleScale*sample)
			s1 = clip_value(s1,-self.sampleScale,self.sampleScale)
			self.wavFile.writeframes(struct_pack(self.packFormat,s1))
			return sample
		else:
			s1 = int(self.sampleScale*sample)
			s1 = clip_value(s1,-self.sampleScale,self.sampleScale)
			s2 = int(self.sampleScale*sample2)
			s2 = clip_value(s2,-self.sampleScale,self.sampleScale)
			self.wavFile.writeframes(struct_pack(self.packFormat,s1))
			self.wavFile.writeframes(struct_pack(self.packFormat,s2))
			return (sample,sample2)

def encode_time(value):
    if value.microsecond > 0:
        val = (
            value.microsecond |
            value.second << 20 |
            value.minute << 26 |
            value.hour << 32
        )
        return DYN_COL_TIME, struct_pack('Q', val)[:6]
    else:
        val = (
            value.second |
            value.minute << 6 |
            value.hour << 12
        )
        return DYN_COL_TIME, struct_pack('I', val)[:3]

 def pack_test(self, string, buffsize):
     """ packs wireless request data for sending it to the kernel """
     buffsize = buffsize - len(string)
     buff = array('c', string+'\0'*buffsize)
     caddr_t, length = buff.buffer_info()
     s = struct_pack('Pii', caddr_t, length, 1)
     return buff, s

def bool_to_bitarray(value):
    """
    Converts a numpy boolean array to a bit array (a string of bits in
    a bytes object).

    Parameters
    ----------
    value : numpy bool array

    Returns
    -------
    bit_array : bytes
        The first value in the input array will be the most
        significant bit in the result.  The length will be `floor((N +
        7) / 8)` where `N` is the length of `value`.
    """
    value = value.flat
    bit_no = 7
    byte = 0
    bytes = []
    for v in value:
        if v:
            byte |= 1 << bit_no
        if bit_no == 0:
            bytes.append(byte)
            bit_no = 7
            byte = 0
        else:
            bit_no -= 1
    if bit_no != 7:
        bytes.append(byte)

    return struct_pack("%sB" % len(bytes), *bytes)

def encode_float(value):
    if isnan(value) or isinf(value):
        raise DynColValueError("Float value not encodeable: {}".format(value))
    encvalue = struct_pack('d', value)

    # -0.0 is not supported in SQL, change to 0.0
    if encvalue == b'\x00\x00\x00\x00\x00\x00\x00\x80':
        encvalue = b'\x00\x00\x00\x00\x00\x00\x00\x00'

    return DYN_COL_DOUBLE, encvalue

def snappy_emit_backref(f, offset, length):
  if 4 <= length <= 11 and offset < 2048:
    f.write(chr(1 | ((length - 4) << 2) | ((offset >> 8) << 5)))
    f.write(chr(offset & 255))
  else: # a back offset with offset > 65536 is not supported by this encoder!
    encoded_offset = struct_pack("<H", offset)
    while length > 0:
      curr_len_chunk = min(length, 64)
      f.write(chr(2 | ((curr_len_chunk - 1) << 2)))
      f.write(encoded_offset)
      length -= curr_len_chunk

 def pack_wrq(self, buffsize):
     """ packs wireless request data for sending it to the kernel """
     # Prepare a buffer
     # We need the address of our buffer and the size for it. The
     # ioctl itself looks for the pointer to the address in our
     # memory and the size of it.
     # Dont change the order how the structure is packed!!!
     buff = array('c', '\0'*buffsize)
     caddr_t, length = buff.buffer_info()
     s = struct_pack('Pi', caddr_t, length)
     return buff, s

 def pack_bytes_header(self, size):
     stream = self.stream
     if size < PLUS_2_TO_THE_8:
         stream.write(BYTES_8)
         stream.write(PACKED_UINT_8[size])
     elif size < PLUS_2_TO_THE_16:
         stream.write(BYTES_16)
         stream.write(PACKED_UINT_16[size])
     elif size < PLUS_2_TO_THE_32:
         stream.write(BYTES_32)
         stream.write(struct_pack(UINT_32_STRUCT, size))
     else:
         raise OverflowError("Bytes header size out of range")

 def a_qr_str(self, grupo_cat=None, con_dnis=True):
     """Devuelve la informacion del recuento para almacenar en qr."""
     encoded_data = self.a_tag(grupo_cat, con_dnis)
     datos = bytearray(b"")
     # Agregamos el Token
     datos.append(int(TOKEN, 16))
     # agregamos el largo de los datos en 2 bytes
     len_data = len(encoded_data) * 2
     datos.extend(struct_pack(">H", len_data))
     # metemos el resto de los datos
     datos.extend(encoded_data)
     # lo encodeamos en hexa y lo pasamos a mayúsculas
     todo = encode(datos, "hex_codec").decode().upper()
     return todo

 def pack_map_header(self, size):
     stream = self.stream
     if size < PLUS_2_TO_THE_4:
         stream.write(TINY_MAP[size])
     elif size < PLUS_2_TO_THE_8:
         stream.write(MAP_8)
         stream.write(PACKED_UINT_8[size])
     elif size < PLUS_2_TO_THE_16:
         stream.write(MAP_16)
         stream.write(PACKED_UINT_16[size])
     elif size < PLUS_2_TO_THE_32:
         stream.write(MAP_32)
         stream.write(struct_pack(UINT_32_STRUCT, size))
     else:
         raise OverflowError("Map header size out of range")

 def pack_string_header(self, size):
     stream = self.stream
     if size < PLUS_2_TO_THE_4:
         stream.write(TINY_STRING[size])
     elif size < PLUS_2_TO_THE_8:
         stream.write(STRING_8)
         stream.write(PACKED_UINT_8[size])
     elif size < PLUS_2_TO_THE_16:
         stream.write(STRING_16)
         stream.write(PACKED_UINT_16[size])
     elif size < PLUS_2_TO_THE_32:
         stream.write(STRING_32)
         stream.write(struct_pack(UINT_32_STRUCT, size))
     else:
         raise OverflowError("String header size out of range")

 def flush(self, end_of_message=False):
     """ Flush everything written since the last chunk to the
     stream, followed by a zero-chunk if required.
     """
     output_buffer = self.output_buffer
     if output_buffer:
         lines = [struct_pack(">H", self.output_size)] + output_buffer
     else:
         lines = []
     if end_of_message:
         lines.append(b"\x00\x00")
     if lines:
         self.raw.writelines(lines)
         self.raw.flush()
         del output_buffer[:]
         self.output_size = 0

def encode_int(value):
    if value < 0:
        dtype = DYN_COL_INT
        encvalue = -(value << 1) - 1
        if value < -(2 ** 32 - 1):
            raise DynColValueError("int {} out of range".format(value))
    else:
        if value <= (2 ** 63 - 1):
            dtype = DYN_COL_INT
            encvalue = value << 1
        elif value <= (2 ** 64 - 1):
            dtype = DYN_COL_UINT
            encvalue = value
        else:
            raise DynColValueError("int {} out of range".format(value))

    to_enc = []
    while encvalue:
        to_enc.append(encvalue & 0xff)
        encvalue = encvalue >> 8
    return dtype, struct_pack('B' * len(to_enc), *to_enc)

    def binoutput(self, value, mask):
        if np.any(mask):
            vo_warn(W39)

        value = value.flat
        bit_no = 7
        byte = 0
        bytes = []
        for v in value:
            if v:
                byte |= 1 << bit_no
            if bit_no == 0:
                bytes.append(byte)
                bit_no = 7
                byte = 0
            else:
                bit_no -= 1
        if bit_no != 7:
            bytes.append(byte)

        assert len(bytes) == self._bytes

        return struct_pack("%sB" % len(bytes), *bytes)