值錯誤：無法將str轉換爲浮點數PYTHON

Question

這是我的代碼。我不明白爲什麼我會得到這個錯誤以及如何糾正它。 出現錯誤：totals = entrant + float(tot) 這裏是我的全碼：

def total(): 
    File = open("argent.txt","r") 
    File = File.read() 
    tot = File 
    print("You have",tot,"£ in your account") 

def add(): 
    entrant = float(input("How many do you want to add to your account? ")) 

    with open("argent.txt", 'r') as f: 
     tot = f.read().rstrip('\n') 

    print("You have ",tot,"£ in your account") 
    totals = entrant + float(tot) 
    print(totals) 

    with open("argent.txt", 'w') as f: 
     output = str(totals) 
     f.write(output) 
add() 

在此先感謝。

Answer 1

在您的情況下，函數read()不僅可以讀取字符20，還可以讀取附加到它的新行字符。

所以變量tot包含的值不能轉換爲數字。

嘗試

tot = tot.strip() 

使用它之前。

Answer 2

未來，請儘量避免使用File作爲file type變量。

entrant = float(input("How many do you want to add to your account? ")) 

with open("argent.txt", 'r') as f: 
    tot = f.read().rstrip('\n') 

print("You have ",tot,"£ in your account") 
totals = entrant + float(tot) 
print(totals) 

with open("argent.txt", 'w') as f: 
    output = str(totals) 
    f.write(output) 

通過使用with open該文件在下面的代碼後關閉。

編輯：修正了'w'從float文件輸出到str