索引器错误：列表索引超出范围Python 3.5.2

Question

我目前正在测试我的程序，这个程序基本上是用python中的CSV模块读写一个‘stock’文件。但是我得到了这个错误：
IndexError: list index out of range

错误来自程序的这一部分：

def GTIN8Test(): # function validates GTIN
digit8 = input("Please enter the GTIN-8 of the product you want to modify in the stock file: ") # input for GTIN
while digit8.isdigit is False or len(digit8) > 8 or len(digit8) < 8: # checks length of GTIN and characters
    digit8 = input("Invalid GTIN-8! Please enter a valid GTIN ")
V1 = int(digit8[0])
V2 = int(digit8[1])
V3 = int(digit8[2])
V4 = int(digit8[3]) # validates GTIN
V5 = int(digit8[4])
V6 = int(digit8[5])
V7 = int(digit8[6])
V8 = int(digit8[7])
V1a = V1 * 3
V3a = V3 * 3
V5a = V5 * 3
V7a = V7 * 3
T1 = V1a + V2 + V3a + V4 + V5a + V6 + V7a + V8 
T2 = T1 % 10
if T2 != 0:
    print("Your GTIN-8 code",digit8,"is not valid!")
    GTIN8Test() # calls function so user can enter another GTIN if theirs is invalid
else:
    import csv # imports CSV for reading files
    s = open("stock.txt") # opens stock file
    counter = 0 # sets counter to 0
    while counter != 3: # while counter is not = to 3 this loop keeps running
        for stock in csv.reader(s): # checks each line in the stock file6
            if digit8 == stock[0]:
                print("GTIN-8 is valid and is found in the stock file")
                StockMod(digit8) # StockMod is called, carring the GTIN as a paramter
            else:
                counter = counter + 1 # if no matches on a line are found 1 is added to the counter. 
    print("GTIN valid but not found in stock file!") # message displays when counter = 3.
    s.close() # closes stock file       

错误似乎是在函数末尾触发的：

^{pr2}$

抱歉，如果有任何格式错误！在

提前谢谢。在

编辑：

以下是完整的错误：

Traceback (most recent call last): File "C:\Users\Mavro\Documents\School Work\GCSE COURSEWORK\Computer Science\Task 3\Task3MOD (1).py", line 84, in <module> GTIN8Test() # calls GTIN8Test for StockMod File "C:\Users\Mavro\Documents\School Work\GCSE COURSEWORK\Computer Science\Task 3\Task3MOD (1).py", line 29, in GTIN8Test if digit8 == stock[0]: IndexError: list index out of range

Answer 1

“是怎么做到的？”股票.txt“看起来像？也许文件开头有空行？csv.reader会返回空列表。在这种情况下，您可以在这行之前添加s.readline（）：

for stock in csv.reader(s):

如果每行不是空的，也可以检查：

^{2}$