Question

我写了一个非常简单的脚本来获取购买的产品数量，成本和平均值：

from __future__ import division

def print_purchase(arg1, arg2, arg3):
    print """You bought %r products and paid %r,
             for an average of %d""" % (arg1, arg2, arg3)

quantity = raw_input("How many products did you buy?")
cost = raw_input("How much did you pay?")
average = quantity/cost

print_purchase(quantity, cost, average)

直到它必须执行除法才有效。我试图通过几种方式“修改”代码，以便它可以执行这些操作（导入除法等），但我仍然无法使其工作：

Traceback (most recent call last):
  File "purchase.py", line 9, in <module>
    average = quantity/cost
TypeError: unsupported operand type(s) for /: 'str' and 'str'

Answer 1

您应该将string类型原始输入转换为数字类型（float或int）;

from __future__ import division

def print_purchase(arg1, arg2, arg3):
    print """You bought %r products and paid %r,
             for an average of %d""" % (arg1, arg2, arg3)
try:
    quantity = float(raw_input("How many products did you buy?"))
    cost = float(raw_input("How much did you pay?"))
except (TypeError, ValueError): 
    print ("Not numeric. Try Again.")      

print_purchase(quantity, cost, average) 
average = quantity/cost

Answer 2

函数raw_input()会将输入的值作为字符串返回，因此您必须将其转换为数字（int或float）：

quantity = int(raw_input("How many products did you buy?"))
cost = float(raw_input("How much did you pay?"))

Python中不支持的操作数类型

2 个答案: