Question

我正在创建一个程序，要求用户选择要在程序中运行的文件，但是当输入不存在的文件名时，我无法阻止程序崩溃。我尝试过try语句和for循环，但是它们都给出了错误。我选择文件的代码如下：

data = []
print "Welcome to the program!"
chosen = raw_input("Please choose a file name to use with the program:")
for line in open(chosen):
    our_data = line.split(",")

    data.append(our_data)

Answer 1

添加例外：

data = []
print "Welcome to the program!"
chosen = raw_input("Please choose a file name to use with the program:")
try:
  for line in open(chosen):
      our_data = line.split(",")

      data.append(our_data)
except IOError:
      print('File does not exist!')

Answer 2

如果不使用例外，您只需检查文件是否存在，如果不存在则再次询问。

import os.path 

data = []
print "Welcome to the program!"
chosen='not-a-file'
while not os.path.isfile(chosen):
    if chosen != 'not-a-file':
        print("File does not exist!")
    chosen = raw_input("Please choose a file name to use with the program:")
for line in open(chosen):
    our_data = line.split(",")

    data.append(our_data)

Answer 3

RTM

import sys

try:
    f = open('myfile.txt')
    s = f.readline()
    i = int(s.strip())
except IOError as e:
    print "I/O error({0}): {1}".format(e.errno, e.strerror)
except ValueError:
    print "Could not convert data to an integer."
except:
    print "Unexpected error:", sys.exc_info()[0]
    raise

无法阻止程序因用户输入的错误文件而崩溃

3 个答案: