当类不继承任何内容时，从命令行调用 python 脚本会出现语法错误，这是为什么？

发布于 2025-01-07 08:00:49 字数 581 浏览 4 评论 0原文

这个问题（对我来说）没有任何实际意义。我只是偶然发现了这一点，我很好奇其背后的机制。我得到了以下示例脚本：

#!/usr/bin/env python
"""
just an example
"""

class exampleClass():
    'this is just an example'


if __name__ == '__main__':
    print(__doc__)

在 eclipse 中运行此打印“只是一个示例”。但是，当我尝试在终端中运行它时，出现以下错误：

File "./temp.py", line 6
   class exampleClass():
                       ^
  SyntaxError: invalid syntax

现在，当我将示例脚本中的类更改为从 dict 继承

class exampleClass(dict):

并从命令行运行它时，它还会打印“只是一个示例”。那么为什么类必须继承某些东西才能从命令行工作，而不是从 Eclipse 继承呢？

原文

This question has (for me) no real implication. I just found this out by coincidence and I am curious about the mechanics behind it. I got the folling example script:

#!/usr/bin/env python
"""
just an example
"""

class exampleClass():
    'this is just an example'


if __name__ == '__main__':
    print(__doc__)

Running this in eclipse print "just an example". However, when I try to run this in the terminal I get the following error:

File "./temp.py", line 6
   class exampleClass():
                       ^
  SyntaxError: invalid syntax

Now, when I change the class in the example script to inherit from dict

class exampleClass(dict):

and run it from the commandline it also prints "just an example".
So why do classes have to inherit something to work from commandline, but not from eclipse?

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烈酒灼喉 2025-01-14 08:00:49

根据 Python 2.7.2 语法，以下语法不正确：

class exampleClass():
    'this is just an example'

它应该是

class exampleClass:
    'this is just an example'

或者

class exampleClass(object): # or `dict' etc
    'this is just an example'

很可能您正在使用两个不同版本的 Python 解释器，并且由于某种原因，其中一个解释器允许无效语法，而另一个则不允许。

According to the Python 2.7.2 grammar, the following syntax is incorrect:

class exampleClass():
    'this is just an example'

It should be either

class exampleClass:
    'this is just an example'

class exampleClass(object): # or `dict' etc
    'this is just an example'

In all probability you're using two different versions of the Python interpreter, and for some reason one of the interpreters is allowing the invalid syntax and the other isn't.

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