首页 \ 问答 \ Python创建目录失败(Python create directory failing)

Python创建目录失败(Python create directory failing)

我正在使用一些非常标准的代码:

 1   if not os.path.exists(args.outputDirectory):
 2       if not os.makedirs(args.outputDirectory, 0o666):
 3           sys.exit('Fatal: output directory "' + args.outputDirectory + '" does not exist and cannot be created')

我删除目录和检查1滴到2 。 我超越了一步,并在3点击错误消息。

但是,当我检查时,目录已成功创建。

drwxrwsr-x 2 userId userGroup  4096 Jun 25 16:07 output/

我错过了什么?


I am using some pretty standard code:

 1   if not os.path.exists(args.outputDirectory):
 2       if not os.makedirs(args.outputDirectory, 0o666):
 3           sys.exit('Fatal: output directory "' + args.outputDirectory + '" does not exist and cannot be created')

I remove the directory and the check at 1 drops through to 2. I one-step beyond that and hit the error message at 3.

However, when I check, the directory was created successfully.

drwxrwsr-x 2 userId userGroup  4096 Jun 25 16:07 output/

What am I missing??


原文:https://stackoverflow.com/questions/31052887
更新时间:2020-03-26 12:04

最满意答案

os.makedirs不表示它是否通过其返回值成功:它总是返回None

NoneFalse -y,因此, not os.makedirs(args.outputDirectory, 0o666)始终为True ,这会触发您的sys.exit代码路径。


幸运的是,你不需要任何这些。 如果os.makedirs失败,它将抛出一个OSError

你应该捕获异常,而不是检查返回值:

try:
    if not os.path.exists(args.outputDirectory):
        os.makedirs(args.outputDirectory, 0o666):
except OSError:
    sys.exit('Fatal: output directory "' + args.outputDirectory + '" does not exist and cannot be created')

如果未引发OSError则表示已成功创建目录。


os.makedirs does not indicate whether it succeeded through its return value: it always returns None.

None is False-y, therefore, not os.makedirs(args.outputDirectory, 0o666) is always True, which triggers your sys.exit code path.


Fortunately, you don't need any of that. If os.makedirs fails, it'll throw an OSError.

You should catch the exception, not check the return value:

try:
    if not os.path.exists(args.outputDirectory):
        os.makedirs(args.outputDirectory, 0o666):
except OSError:
    sys.exit('Fatal: output directory "' + args.outputDirectory + '" does not exist and cannot be created')

If no OSError is thrown, that means the directory was successfully created.

2015-06-25

相关文章

更多

最新问答

更多
  • css在元素之前中断列而不破坏包装器(css break column before element without breaking the wrapper)
  • 如何在Xamarin共享项目中使用自定义渲染器(How to use Custom Renderer in Xamarin Shared Project)
  • 如何为特定表中的特定字段设置唯一?(How to set unique for specific field from specific table?)
  • Google SDK iOS - sign()方法完成处理程序(Google SDK iOS - sign() method completion handler)
  • 在具有接口{}值的地图上实现String()(Implement String() on a map with interface{} values)
  • 检查数据库中是否已存在用户名(Check if username already exist in DB)
  • 使用javascript进行ajax调用时阻止用户交互(Block user interaction while doing ajax call using javascript)
  • 什么'if(err)'在Javascript中精确测试?(What does 'if (err)' tests precisely in Javascript?)
  • jQuery mouseleave无法正常工作(jQuery mouseleave not working)
  • 寻求使用的一些说明(Seeking some clarification on use of )
  • 将数组传递给注释的语法(syntax for passing array to annotation)
  • 用于从两个日期范围之间的文件中提取数据的Shell脚本(Shell script to extract data from file between two date ranges)
  • 元素隐藏但父()没有(Element hides but parent() not)
  • 如何使用Google App Engine Java平台开发web ui(How to develop web ui with Google App Engine Java platform)
  • 对于OWL A级;(For an OWL class A; Getting all properties that A is their domain)
  • Excel VBA公式格式问题(Excel VBA Formula Format Issue)
  • ORA - 02287序列号不允许在这里(ORA - 02287 sequence number not allowed here)
  • Github拉忽略特定文件(Github Pull Ignore Specific File)
  • SQL CONVERT函数在SQL Server中工作但不在应用程序中(SQL CONVERT function working in SQL Server but not in application)
  • backbone.js适用于大型应用程序(backbone.js for large applications)
  • 防止程序关闭(Preventing program from closing)
  • 生成不带图像的heightMap(Generating a heightMap without an Image)
  • Bootstrap - 如何将包含文本的div居中?(Bootstrap - How to center div that has text inside it?)
  • Android - 片段findViewById()总是null?(Android - Fragment findViewById() always null?)
  • 确定CSS中的高度(Figuring out heights in CSS)
  • 使用__autoload包含类和使用命名空间(Use __autoload to include class and use namespace)
  • setTimeout()不允许我传递文本值[重复](setTimeout() doesn't allow me to pass text values [duplicate])
  • 在NSUserDefault中恢复值(Restoring value in NSUserDefault)
  • 知道如何将这种下沉的悬停效果添加到图像/链接吗?(Any idea how to add this sinking hover effect to an image/link?)
  • 在XIB中淡入/淡出UISegmentedControl(fade in/fade out UISegmentedControl in XIB)