打印最高平均值 - 「不支持的操作數類型爲+：'int'和'str'」

Question

我試圖實現從最高到最低打印平均分的輸出。但是，當我運行該程序時，出現錯誤：unsupported operand type(s) for +: 'int' and 'str'。

我是相當新的Python和我不知道我在哪裏出了毛病，這個代碼：

f = open('ClassA.txt', 'r') 
#a empty dictionar created 
d = {} 
#loop to split the data in the ext file 
for line in f: 
    columns = line.split(": ") 
    #identifies the key and value with either 0 or 1 
    names = columns[0] 
    scores = columns[1].strip() 
    #appends values if a key already exists 
    tries = 0 
    while tries < 3: 
     d.setdefault(names, []).append(scores) 
     tries = tries + 1 
if wish == '3': 
    for names, v in sorted(d.items()): 
     average = sum(v)/len(v) 
     print ("{} Scored: {}".format(names,average)) 

的錯誤，我得到：

Traceback (most recent call last): 
    File "N:\task 3 final.py", line 33, in <module> 
    average = sum(v)/len(v) 
TypeError: unsupported operand type(s) for +: 'int' and 'str' 

Answer 1

你有串在您的字典，但sum()將以數字0開頭，以僅累加數值：

>>> sum(['1', '2']) 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
TypeError: unsupported operand type(s) for +: 'int' and 'str' 

轉換你的分數爲數字，無論是int()或float()根據您的格式：

scores = int(columns[1].strip())