Python中如何應用類正確

Question

我寫了下面的類和程序：

class Coordinate(object): 
    def __init__(self,x,y): 
     self.x_coordinate = x 
     self.y_coordinate = y 

class CoordinatRow(object): 
    def __init__(self): 
     self.coordinaterow = [] 

    def add_coordinaterow(self, coordinate): 
     self.coordinaterow.append(coordinate) 

    def weave(self,other): 
     lijst = [] 
     for i in range(len(self.coordinaterow)): 
      lijst.append(self.coordinaterow[i]) 
      lijst.append(other.row[i]) 
     coordinaterow = lijst 
     print coordinaterow 

程序：

from Coordinates import Coordinate, CoordinatRow 
from ipy_lib import file_input 

'''functies''' 

def split_and_add(invoer): 
    rij = invoer.split('=') 
    for line in rij: 
     process_row(line) 

def process_row(line): 
    temp_coordinate_row = CoordinatRow() 
    rij = line.split() 
    for coordinate in rij: 
     coor = process_coordinate(coordinate) 
     temp_coordinate_row.add_coordinaterow(coor) 
    return temp_coordinate_row 

def process_coordinate(coordinate): 
    idunno = coordinate.split(',') 
    return Coordinate(int(idunno[0]),int(idunno[1])) 

'''programma''' 
bestand = file_input() 
split_and_add(bestand) 
rows = split_and_add(bestand) 
for row in rows: 
    row.weave(row) 

輸入如下所示：

5,4 4,5 8,7=6,3 3,2 9,6 4,3=7,6=9,8=5,5 7,8 6,5 6,4 

ECH行seprated通過=。我想用這樣的下一行編織每行：

5.4, 4.5, 8.7 weave with 6.3, 3.2, 9.6, 4.3 
5.4, 6.3, 4.5, 3.2, 8.7, 9.6, 4.3 

和下一行到這個新行。

問題在於我認爲應用我的課程的方式。我得到這個錯誤：

for row in rows: 
TypeError: 'NoneType' object is not iterable 

這是怎麼回事？

Answer 1

如果你不希望使用產

def split_and_add(invoer): 
    rij = invoer.split('=') 
    rows = [] 
    for line in rij: 
     rows.append(process_row(line)) 
    return rows 

你的第二個問題，你可能想要做這樣的事情：

for row in range(0,len(rows)-1): 
    rows[row].weave(rows[row+1]) 

Answer 2

def split_and_add(invoer): 
    rij = invoer.split('=') 
    for line in rij: 
     yield process_row(line)