如何继续 try/except

Question

我目前正在学习“try”和“except”的概念，但我有一个小问题。

def sum_file():
    try:
        with open("text.txt") as entry:
            result = 0
            try:
                for line in entry:
                    result += int(line.strip())
                    print(result)
            except ValueError:
                print("Non-integer number entered")
    except:
        print("Non-existent file.")

文件的每一行都是一个数字，有些数字是整数，有些是浮点数。代码正确地对第一个整数求和，但是当第一个浮点数出现时程序停止，当有更多行时。如何修改代码使其继续运行？

Answer 1

您需要将第二个 try 块放入循环中：

def sum_file():

    try:
        with open("text.txt") as entry:
            result = 0
            for line in entry:
                try:
                    result += int(line.strip())
                    print(result)
                except ValueError:
                    print("Non-integer number entered")
    except:
        print("Non-existent file.")

Answer 2

或者您可以使用 re 来帮助您。

re.match(r".*\D+.*", line) 匹配任何包含一个或多个 not [0-9] 字符的行

from io import StringIO
import re

text_txt = """\
3.1
123
4 b 5 6
     7.2   
c'] ? 9
  10
"""


def sum_file():
    with StringIO(text_txt) as f:
        result_list = []
        for line in [_.strip() for _ in f]:
            m = re.match(r".*\D+.*", line)
            print("Non-integer number entered") if m else (print(line), result_list.append(int(line)))
        print(f'result: {sum(result_list)}') if result_list else None

sum_file()

输出

Non-integer number entered
123
Non-integer number entered
Non-integer number entered
Non-integer number entered
10
result: 133

如何继续 try/except

How to continue a try/except

python

try-except