使用异常处理防止系统崩溃时出现几行答案

【问题标题】：several lines appearing when using exception handling to prevent system from crashing使用异常处理防止系统崩溃时出现几行
【发布时间】：2020-08-13 08:36:43
【问题描述】：

我正在尝试使用异常处理来防止我的系统崩溃，我使用了以下代码，其中该 csv 文件实际上并不存在。但是系统一直在给我答案。有人可以帮我更正我的代码吗....请帮帮我

这些是我的源代码：

while True:
    try:
        import pandas as pd  # data processing, csv file I/O(e.g pd.read_csv)

        df = pd.read_csv('C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv')
        print(df)
    except Exception as err:
            print("Uh oh, please send me this message: '{}'" .format(err))

结果：

Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
Uh oh, please send me this message: '[Errno 2] File b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv' does not exist: b'C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv''
..................

【问题讨论】：

为什么while True 块中有代码？如果示例中没有包含它的原因，您可以在except 块中添加break 以在出现异常时退出循环。

标签： python python-3.x exception error-handling

【解决方案1】：

捕获期望意味着您的系统不会退出并显示相应的错误代码。相反，它会执行您在异常行中的任何操作并继续执行您的代码。来自docs：

如果在try子句执行过程中发生异常，其余的该子句被跳过。然后如果它的类型与名为的异常匹配在 except 关键字之后，执行 except 子句，然后在 try 语句之后继续执行。

这就是为什么你永远不会离开 while 循环的原因。这是对循环的快速修复：

while True:
    try:
        import pandas as pd  # data processing, csv file I/O(e.g pd.read_csv)

        df = pd.read_csv('C:/Users/User/Desktop/Coding/parsehubjsonfileeg/assd.csv')
        print(df)
    except Exception as err:
        print("Uh oh, please send me this message: '{}'" .format(err))
        break

如果找不到您的 csv，进一步的调整取决于您想要做什么。

【讨论】：