python - 如何在循环外部获取 for 循环中定义的变量？ -Python

Question

当我运行此 Python 代码时，我收到一个名称错误。但在这段代码中，我试图获取在 for 循环 (get) 中定义的变量以在循环外部使用。如何在 for 循环之外使用此变量 (get)？

file = open("f:/py/price.txt", "r")

valRange = 0
cal = 0
totalCst = 0
itmCnt = 0
while (valRange < 10):
     idNumber = int(input("Enter Id number: "))
     for line in file:
          if line.startswith(str(idNumber)):
               get = line.split("=")[1]
          break
     quantity = int(input("Enter qantity: "))
     cal = quantity * int(get)
     totalCst += cal
     itmCnt += quantity

print (totalCst)

Answer 1

只需在循环之前初始化变量即可。此外，break 命令不在 if 中。尝试:

file = open("f:/py/price.txt", "r")

valRange = 0
cal = 0
totalCst = 0
itmCnt = 0
while (valRange < 10):
     idNumber = int(input("Enter Id number: "))
     get = 0
     for line in file:
          if line.startswith(str(idNumber)):
               get = line.split("=")[1]
               break
     quantity = int(input("Enter qantity: "))
     cal = quantity * int(get)
     totalCst += cal
     itmCnt += quantity

print (totalCst)