class - 如何让继承从父类到子类python34

Question

我正在尝试了解继承的概念。我试图在父级(gps 类)和子级(print_gps 类)中完成工作。我正在使用 xlsxwriter 将 GPS 数据保存到 Excel 文件中。

出于某种原因，我无法从 gps 类获取数据以在 print_gps 类中使用。我是不是少了一步？

import os
import csv
from csv import *
import numpy
import matplotlib
from numpy import *
from matplotlib import *
import matplotlib.pyplot as plt
from matplotlib.pylab import *
import numpy as np
#import nmea_defs
#from nmea_defs import *


#to export to excel
import xlsxwriter
from xlsxwriter.workbook import Workbook

#to get the csv converter functions
import os
import subprocess
import glob

#to get the datetime functions
import datetime
from datetime import datetime
from pytz import timezone
import time
import calendar


#creates the path needed for incoming and outgoing files
path_in = 'C:/Python34/gps_txts/'
path_out = 'C:/Python34/output_files/'

#prints all the data in the file if you want
q_show_content = input('Print list of files type y:')
if q_show_content == 'y':
    for root, dirs, files in os.walk(path_in):
          print(root, dirs, files)
else:
    print('ok')


data = []  #empty because we will store data into it



#Reads a CSV file and return it as a list of rows
def read_csv_file(filename):
    """Reads a CSV file and return it as a list of rows."""

    for row in csv.reader(open(filename)):
        data.append(row)
    return data

#request of what file to look at
print ("- - - - - - - - - - - - -")
data_file = input('Which file do you want to look at?')

f = open(path_in + data_file)
read_it = read_csv_file(path_in + data_file)

with f as csvfile:
    readCSV = csv.reader(csvfile,delimiter=',')
    plots = csv.reader(csvfile, delimiter=',')


#creates the workbook
output_filename = input('output filename:')
workbook = xlsxwriter.Workbook(path_out + output_filename + '.xlsx')
worksheet = workbook.add_worksheet()

#formatting definitions
bold    = workbook.add_format({'bold': True})
date_format = workbook.add_format({'num_format': "m/d/yyyy hh:mm:ss"})

#print number of rows
print ("- - - - - - - - - - - - -")
rows = len(read_it)
print (data_file, " has "+ str(rows) + " rows of data")
print ("- - - - - - - - - - - - -")

#Counts the number of times a GPS command is observed
def list_gps_commands(data):
    """Counts the number of times a GPS command is observed.

Returns a dictionary object."""

    gps_cmds = dict()
    for row in data:
        try:
            gps_cmds[row[0]] += 1 
        except KeyError:
            gps_cmds[row[0]] = 1

    return gps_cmds

print(list_gps_commands(read_it))
print ("- - - - - - - - - - - - -")


 #Function process_gps_data for GPS 

class gps:
    print ("- - - - - - - - - - - - -")
    print('We got class')
    print ("- - - - - - - - - - - - -")



    def process_gprmc_data(data):
        """Processes GPS data, NMEA 0183 format.
    Returns a tuple of arrays: latitude, longitude, velocity [km/h],
    time [sec] and number of satellites.
    See also: http://www.gpsinformation.org/dale/nmea.htm.
    """
        NMI = 1852.0
        latitude  = []
        longitude = []
        altitude  = []
        velocity  = []
        timestamp = []
        num_sats  = []

        print ("- - - - - - - - - - - - -")
        print('process_gprmc_data')
        print ("- - - - - - - - - - - - -")
        for row in data:

            if row[0] == '$GPRMC':     # Valid position/time sentence
                y = (float(row[3][0:2]) + float(row[3][2:])/60.0)
                if row[4] == "S":
                    y = -y
                latitude.append(y)
                x = (float(row[5][0:3]) + float(row[5][3:])/60.0)
                if row[6] == "W":
                    x = -x
                longitude.append(x)
                print('x,y:',x,y)
                velocity.append(float(row[7])*NMI/1000.0)
                gpstime = row[1][0:6]                     # hhmmss
                gdate = row[9]                            # ddmmyy
                gpsdate = gdate[4:6]+gdate[2:4]+gdate[0:2]  # yymmdd
                real_time =gpsdate + gpstime
                add_date_time = datetime.strptime(real_time, "%y%m%d%H%M%S")
                print(add_date_time)
                timestamp.append(add_date_time)
        print ("- - - - - - - - - - - - -")
        print('arrays in')
        print ("- - - - - - - - - - - - -")
        return (array(latitude), array(longitude), array(velocity), array(timestamp))

    #had to create another function to print results
class print_gps(gps):
    def __init__(self):
        self.gps = gps()        
        super(print_gps, self).__init__() 

    def process_gprmc_data(self):     
        self.gps.process_gprmc_data()
        # how to call process_gprmc_data()
        (lati, long, v, t_stamp) = self.gps.process_gprmc_data(data)
#    def print_gprmc(process_gprmc_data):
        print('got definitions in')
        print ("- - - - - - - - - - - - -")
        print('lati:',lati)
        print ("- - - - - - - - - - - - -")
        print('long:',long)
        print ("- - - - - - - - - - - - -")
        print('v:',v)
        print ("- - - - - - - - - - - - -")
        print('date:', t_stamp)
        print ("- - - - - - - - - - - - -")
        if rows > 200:
            print('Big file please wait...thinking')

        #sets up the header row
        worksheet.write('A1','TimeStamp',bold)
        worksheet.write('B1', 'Latitude',bold)
        worksheet.write('C1', 'Longitude',bold)
        worksheet.write('D1', 'Velocity',bold)
        worksheet.autofilter('A1:D1')   #dropdown menu created for filtering

        # Create a For loop to iterate through each row in the XLS file, starting at row 2 to skip the headers
        for r, row in enumerate(data, start=1):  #where you want to start printing results inside workbook
            for c, col in enumerate(data):
                worksheet.write_column(r,0, t_stamp, date_format)
                worksheet.write_column(r,1, lati)
                worksheet.write_column(r,2, long)
                worksheet.write_column(r,3, v)


        workbook.close()
        f.close()
        print('XLSX file named ' + output_filename + ' was created')


#processing piece

command = input("What type do you want to look at?")
if command == '$GPRMC':
#    nmea_defs.gps(data)
    gps.process_gprmc_data(data)
    print_gps.process_gprmc_data(data)


else:
    print("Invalid type:", command)

我得到这个结果和错误:

process_gprmc_data
- - - - - - - - - - - - -
x,y: 139.64428333333333 35.892158333333334
2001-07-18 00:24:54
x,y: 139.64430166666668 35.892201666666665
2002-07-18 00:24:56
x,y: 4.8333433333333335 45.00351833333333
2003-08-14 10:47:09
x,y: 5.00001 51.00351833333333
2004-08-14 10:47:15
- - - - - - - - - - - - -
arrays in
- - - - - - - - - - - - -
Traceback (most recent call last):
  File "C:\Python34\choose_nmea.py", line 222, in <module>
    print_gps.process_gprmc_data(data)
  File "C:\Python34\choose_nmea.py", line 171, in process_gprmc_data
    self.gps.process_gprmc_data()
AttributeError: 'list' object has no attribute 'gps'

Answer 1

您的程序存在多个问题。

1。缺少 self

在class gps和print_gps中更改:

def process_gprmc_data(data):

进入:

def process_gprmc_data(self, data):

2。使用CamleCase作为类名

将gps重命名为GPS，将print_gps重命名为PrintGPS

3。不需要 __init__() 调用

因为GPS没有__init__()，所以不需要在PintGPS<中调用super()__init__()/.

4。使用实例，而不是类

更改:

gps.process_gprmc_data(data)
print_gps.process_gprmc_data(data)

进入:

gps = GPS()
gps.process_gprmc_data(data)
print_gps = PrintGPS()
print_gps.process_gprmc_data(data)

5。不要将父类的实例作为子类的属性

当您使用继承时，这没有多大意义:

self.gps = gps() 

您将通过继承从父级获取方法，并通过 super() 调用它们(请参阅下面的示例代码。)

工作示例

注意:由于缺少信息，我跳过了一些模式的实现。

完整的工作代码:

from numpy import array

class GPS:

    def process_gprmc_data(self, data):
        """Processes GPS data, NMEA 0183 format.
    Returns a tuple of arrays: latitude, longitude, velocity [km/h],
    time [sec] and number of satellites.
    See also: http://www.gpsinformation.org/dale/nmea.htm.
    """
        NMI = 1852.0
        latitude  = []
        longitude = []
        altitude  = []
        velocity  = []
        timestamp = []
        num_sats  = []

        print ("- - - - - - - - - - - - -")
        print('process_gprmc_data')
        print ("- - - - - - - - - - - - -")
        for row in data:

            if row[0] == '$GPRMC':     # Valid position/time sentence
                y = (float(row[3][0:2]) + float(row[3][2:])/60.0)
                if row[4] == "S":
                    y = -y
                latitude.append(y)
                x = (float(row[5][0:3]) + float(row[5][3:])/60.0)
                if row[6] == "W":
                    x = -x
                longitude.append(x)
                print('x,y:',x,y)
                velocity.append(float(row[7])*NMI/1000.0)
                gpstime = row[1][0:6]                     # hhmmss
                gdate = row[9]                            # ddmmyy
                gpsdate = gdate[4:6]+gdate[2:4]+gdate[0:2]  # yymmdd
                real_time =gpsdate + gpstime
                add_date_time = datetime.strptime(real_time, "%y%m%d%H%M%S")
                print(add_date_time)
                timestamp.append(add_date_time)
        print ("- - - - - - - - - - - - -")
        print('arrays in')
        print ("- - - - - - - - - - - - -")
        return (array(latitude), array(longitude), array(velocity), array(timestamp))

    #had to create another function to print results
class PrintGPS(GPS):

    def process_gprmc_data(self, data):
        # how to call process_gprmc_data()
        (lati, long, v, t_stamp) = super(PrintGPS, self).process_gprmc_data(data)

        print('got definitions in')
        print ("- - - - - - - - - - - - -")
        print('lati:',lati)
        print ("- - - - - - - - - - - - -")
        print('long:',long)
        print ("- - - - - - - - - - - - -")
        print('v:',v)
        print ("- - - - - - - - - - - - -")
        print('date:', t_stamp)
        print ("- - - - - - - - - - - - -")


        output_filename = 'test.xlsx'

        print('XLSX file named ' + output_filename + ' was created')

data = 'abc'
gps = GPS()
gps.process_gprmc_data(data)
print_gps = PrintGPS()
print_gps.process_gprmc_data(data)