本文整理汇总了Python中bitstring.BitStream.find方法的典型用法代码示例。如果您正苦于以下问题：Python BitStream.find方法的具体用法？Python BitStream.find怎么用？Python BitStream.find使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类bitstring.BitStream的用法示例。
在下文中一共展示了BitStream.find方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: PacketDecoder
# 需要导入模块: from bitstring import BitStream [as 别名]
# 或者: from bitstring.BitStream import find [as 别名]
class PacketDecoder(object):
HEADER = "0x59"
FOOTER = "0x5254464d"
LENGTH = 56 * 8
PATTERN = "2BH9I8B2I"
packet_store = []
def __init__(self, listener_func):
self.listener_func = listener_func
self.stream = BitStream()
def push(self, byte_array):
self.stream.append(byte_array)
def handle(self):
while True:
if len(self.stream) < self.LENGTH:
break
# Look for a header
header_pos = self.stream.find(self.HEADER)
if header_pos:
header_pos = header_pos[0]
else:
self.stream.clear()
break
end_pos = header_pos + self.LENGTH
if len(self.stream) < end_pos:
# Not Enough Data
break
# Extract potential packet
potential_packet = self.stream[header_pos:end_pos].bytes
valid_packet = self.analyze_packet(potential_packet)
if valid_packet:
self.stream = self.stream[end_pos:]
else:
self.stream = self.stream[header_pos + 1 :]
self.save_packets()
self.packet_store = []
def analyze_packet(self, byte_string):
if len(byte_string) != 56:
return
data = struct.unpack(self.PATTERN, byte_string)
header = data[0]
footer = data[21]
if hex(header) == self.HEADER and hex(footer) == self.FOOTER:
if self.validate_checksums(data):
packet = self.create_packet(data)
self.packet_store.append(packet)
return True
return False
def validate_checksums(self, packet_data):
# voltage_checksum = packet_data[12]
# current_checksum = packet_data[13]
# period_checksum = packet_data[14]
# active_checksum = packet_data[15]
# reactive_checksum = packet_data[16]
# apparent_power = packet_data[17]
# phase_angle_checksum = packet_data[18]
# power_factor_checksum = packet_data[19]
# checksum = packet_data[20]
return True
def create_packet(self, packet_data):
flags = packet_data[2]
epoch = packet_data[3]
voltage = packet_data[4] * (2.37748 * 10 ** -4) + -0.14427
current = packet_data[5] * (113240.82786) + 953.97194
period = packet_data[6]
active_power = packet_data[7]
reactive_power = packet_data[8]
apparent_power = packet_data[9]
phase_angle = packet_data[10]
power_factor = packet_data[11]
return Packet(
flags=flags,
epoch=epoch,
voltage=voltage,
current=current,
period=period,
active_power=active_power,
reactive_power=reactive_power,
apparent_power=apparent_power,
phase_angle=phase_angle,
power_factor=power_factor,
)
def save_packets(self):
# submit packets to lib
if self.packet_store:
self.listener_func(self.packet_store)