Python报错TypeError: 'str' object is not callable的原因及解决求助

错误原因 #

你在代码里误用Python内置的input()函数名作为变量名：

input = input('What would you like to buy?\n')

第一次执行这行时，input被赋值为用户输入的字符串。后续执行answer = input('Would you like to continue shopping?\n')时，你实际是在尝试调用一个字符串对象，而字符串无法被当作函数调用，因此抛出TypeError: 'str' object is not callable错误。

修复步骤 #

1. 修改变量名，避免覆盖内置函数
   将存储用户输入的变量名从input改为其他名称，比如user_input，同步更新后续引用该变量的代码：

   user_input = input('What would you like to buy?\n')
   user_input = user_input.lower()
   
   # 同步修改判断逻辑中的变量名
   for item in store:
       if user_input == item[0]:
           print(f'That will be {item[1]} dollars.')
   

2. 修正条件判断的逻辑错误
   你代码中的if answer == 'n' or 'no':写法存在逻辑漏洞——无论answer是什么值，这个条件都会返回True（因为'no'本身是布尔真值）。正确写法应为：

   if answer == 'n' or answer == 'no':
       isBuying = False
   # 或者更简洁的写法
   if answer in ['n', 'no']:
       isBuying = False
   

完整修复后的代码 #

isBuying = True

# Create a map for our store's inventory. Each item in our store will have a string name and a floating point number for its price.
store = [('arrows', 20.00), ('bombs', 40.00), ('heart container', 120.00),
         ('sword', 100.00), ('potion', 15.00)]


# Define a function to print out the store's inventory. This function will take in an inventory.
def PrintStore(inventory):
    # For every item in the inventory, it will print out the item name and price in our formatted way.
    for item in inventory:
        print(' ' * 4 + item[0] + '.' * 3 + ' ' * 4 + str(item[1]))


while isBuying:
    # Use our function to print out our store's inventory.
    PrintStore(store)
    # Ask the user what they would like to buy and store the input in a variable. Lowercase it to prevent case sensitivity.
    user_input = input('What would you like to buy?\n')
    user_input = user_input.lower()

    # For every item in our store, check to see if our input is equal to the item's name. If it is, print out the item's price.
    for item in store:
        if user_input == item[0]:
            print(f'That will be {item[1]} dollars.')

    answer = input('Would you like to continue shopping?\n')
    answer = answer.lower()

    if answer in ['n', 'no']:
        isBuying = False

内容的提问来源于stack exchange，提问作者Rodrigo Ponce