[python]用python获取EXCEL文件内容并保存到DBC

关键词

==python、excel、DBC、openpyxl ==

平台说明

项目	Value
python版本	3.6

背景

在搭建自动化测试平台的时候经常会提取DBC文件中的信息并保存为excel或者其他文件格式，用于自动化测试。本文介绍了如何用python3.6实现获取EXCEL文件内容并保存到DBC。

所需库

1.canmatrix：需要它库来解析 DBC 文件，它提供了对 Controller Area Network (CAN) 数据的解析功能，包括 DBC 文件的支持。
2.openpyxl ：是一个用于读写 Excel 文件的 Python 库。

实现过程

方法1.

1.安装相关库

pip install openpyxl canmatrix

2.代码实现

from openpyxl import load_workbook
import canmatrix

class MyDBC_Obj:
    def __init__ (self,dbc_path,excel_path):
        self.name = "self"
        self.sheet = ""
        self.dbc = ""
        self.dbc_path = dbc_path
        self.excel_path = excel_path

    def read_excel(self):
        workbook = load_workbook(filename = self.excel_path)
        self.sheet = workbook.active

    def generate_dbc(self):
        self.dbc = canmatrix.CanMatrix()
        self.dbc.add_global_defines("BusType","STRING")
        self.dbc.add_define_default("BusType","CAN")
        # 报文发送类型属性以及默认值
        self.dbc.add_frame_defines("GenMsgSendType", 'ENUM "Cyclic", "Event"' )
        self.dbc.add_define_default("GenMsgSendType", "Cyclic")
        self.dbc.add_frame_defines("GenMsgCycleTime", 'INT 0 65535')
        self.dbc.add_define_default("GenMsgCycleTime", "0")

    def write_dbc(self):
        self.read_excel()
        self.generate_dbc()
        ecu_obj = canmatrix.Ecu(self.sheet.cell(1,29).value)
        ecu_obj.name = self.sheet.cell(1,29).value
        
        self.dbc.add_ecu(ecu_obj)
        for i in range(2,self.sheet.max_row+1):
            if self.sheet.cell(row=i,column=1).value == None:
                self.sheet.cell(row=i,column=1).value = self.sheet.cell(row=i-1,column=1).value
                self.sheet.cell(row=i,column=2).value = self.sheet.cell(row=i-1,column=2).value
                self.sheet.cell(row=i,column=3).value = self.sheet.cell(row=i-1,column=3).value
                self.sheet.cell(row=i,column=4).value = self.sheet.cell(row=i-1,column=4).value
                self.sheet.cell(row=i,column=5).value = self.sheet.cell(row=i-1,column=5).value
                self.sheet.cell(row=i,column=6).value = self.sheet.cell(row=i-1,column=6).value
        message_name = ""
        message_id = 0
        message_length = 0
        message_type_is_fd = False
        message_type_is_extended = False
        message_cycle = 0
        message_recive = ""
        frame_obj = canmatrix.Frame()
        signal_obj=canmatrix.Signal()
        for row in self.sheet.iter_rows(min_row=3,values_only=True):            
            signal_name = row[6]
            if signal_name != None:
                signal_obj.name = row[6]
                message_name = row[0]
                message_id = int(row[2],16)
                if row[11] != None:
                    signal_obj.start_bit = int(row[11])
                else:
                    signal_obj.start_bit = 0
                signal_obj.size = int(row[13])
                if row[9] == "Motorola":
                    signal_obj.is_little_endian = False
                else:
                    signal_obj.is_little_endian = True
                signal_obj.initial_value = int(row[21])
                signal_obj.add_attribute("GenSigStartValue",signal_obj.initial_value)
                signale_sendtype = 0
                if row[12] == "Cycle":
                    signale_sendtype = 0
                else:
                    signale_sendtype = 2
                signal_obj.add_attribute("GenSigSendType",signale_sendtype)
                if row[14] == "unsigned":
                    signal_obj.is_float = False
                    signal_obj.is_signed = False
                elif row[14] == "signed":
                    signal_obj.is_float = False
                    signal_obj.is_signed = True
                else:
                    signal_obj.is_float = True
                    signal_obj.is_signed = False

                signal_obj.min = float(row[17])
                signal_obj.max = float(row[18])
                signal_obj.factor = float(row[15])
                signal_obj.offset = float(row[16])
                if row[23] != None:
                    signal_obj.unit = row[23]
                if row[28] == "RX":
                    signal_obj.add_receiver(ecu_obj.name)
                elif row[28] == "TX":
                    message_recive = ecu_obj.name

                message_sig_group_name = row[8]
                if  message_sig_group_name != None:
                    signalGroups = frame_obj.signal_group_by_name(message_sig_group_name)
                    if signalGroups == None:
                        frame_obj.add_signal_group(message_sig_group_name,1,signal_obj.name)
                    else:
                        signalGroups.add_signal(signal_obj)

                if row[24] != None:
                    sigvalue = row[24]
                    st=sigvalue.split("\n")
                    for i in st:
                        if i == "":
                            st.remove(i)
                    d = dict(x.split(":") for x in st)
                    for k, v in d.items():
                        signal_obj.add_values(k,v)             
                frame_obj.add_signal(signal_obj)
                #*********** frame type set ***************
                signal_obj=canmatrix.Signal()

                if row[5] != None:
                    message_length = int(row[5])
                else:
                    message_length = 0
                if row[4] != None:
                    message_cycle = int(row[4])
                if row[1] == "CAN standard":
                    message_type_is_fd = False
                    message_type_is_extended = False
                elif row[1] == "CANFD standard":
                    message_type_is_fd = True
                    message_type_is_extended = False
                elif row[1] == "CAN extended":
                    message_type_is_extended = True
                    message_type_is_fd = False
                elif row[1] == "CANFD extended":
                    message_type_is_extended = True
                    message_type_is_fd = True
            else:
                frame_obj.name = message_name
                frame_obj.size = message_length
                frame_obj.arbitration_id.id = message_id
                frame_obj.cycle_time = message_cycle
                frame_obj.is_fd = message_type_is_fd
                frame_obj.is_j1939 = message_type_is_extended
                if message_recive!= "":
                    frame_obj.add_transmitter(ecu_obj.name)
                self.dbc.add_frame(frame_obj)
                message_name = ""
                message_id = 0
                message_length = 0
                message_type = False
                message_recive = ""
                signalGroups = []
                frame_obj = canmatrix.Frame()

        # 导出到DBC文件
        
        file_out = open(self.dbc_path, "wb")
        canmatrix.formats.dbc.dump(self.dbc,file_out,dbcExportEncoding='utf-8')
        file_out.close()



if __name__ == "__main__":
    dbc_file_path = "excel.dbc"  # Replace with the actual DBC file path
    excel_file_path = "dbc.xlsx"  # Replace with the desired Excel output path
    MyDbc = MyDBC_Obj(dbc_file_path,excel_file_path)
    MyDbc.write_dbc()