What is the most elegant way to check if the directory a file is going to be written to exists, and if not, create the directory using Python? Here is what I tried: import os file_path = "/my/directory/filename.txt" directory = os.path.dirname(file_path) try: os.stat(directory) except: os.mkdir(directory) f = file(filename) Somehow, I missed os.path.exists (thanks kanja, Blai
检查文件将要写入的目录是否存在最优雅的方法是什么，如果不是，使用Python创建目录？ 这是我试过的： import os file_path = "/my/directory/filename.txt" directory = os.path.dirname(file_path) try: os.stat(directory) except: os.mkdir(directory) f = file(filename) 不知何故，我错过了os.path.exists （感谢kanja，Blair和Douglas）。 这是我现在拥有的： def ensure_dir(file_path): dire
This question already has an answer here: How to find the real user home directory using python? 8 answers You want to use os.path.expanduser. This will ensure it works on all platforms from os.path import expanduser home = expanduser("~") If you're on Python 3.5+ you can use pathlib.Path.home(): from pathlib import Path home = str(Path.home())
这个问题在这里已经有了答案： 如何使用python找到真正的用户主目录？ 8个答案 你想使用os.path.expanduser。 这将确保它可以在所有平台上运行 from os.path import expanduser home = expanduser("~") 如果你使用Python 3.5+，你可以使用pathlib.Path.home（）： from pathlib import Path home = str(Path.home())
Is there a way of obtaining the Desktop directory path in a cross-platform way, ideally only using standard modules, in Python? My current Mac OS X + Windows solution is to check which system is running Python with sys.platform and then do the following: Mac OS X can be handled with os.path.join(os.path.expanduser('~'), 'Desktop') . Windows can use the non-standard module wi
有没有办法在Python中以跨平台的方式获取桌面目录路径 ，理想情况下只使用标准模块？ 我目前的Mac OS X + Windows解决方案是使用sys.platform检查哪个系统正在运行Python，然后执行以下操作： 可以使用os.path.join(os.path.expanduser('~'), 'Desktop')处理Mac OS X. Windows可以使用非标准模块win32com或ctypes相关模块winpaths; 有没有一个标准的选择？ 那么Linux呢？ 我会很高兴能在Mac OS X，Wi
I was watching this video (http://pyvideo.org/video/1758/loop-like-a-native-while-for-iterators-genera) where at the end he talks about how the generator expression is the same as the normal generator way, but that doesn't seem to be the case and other topics that I've read that is generator expression vs yield say there is no difference. However from what I can see using yield will yiel
我正在观看这个视频（http://pyvideo.org/video/1758/loop-like-a-native-while-for-iterators-genera），最后他谈到了发生器表达式如何与正常的发电机方式，但似乎并非如此，我已阅读的其他主题是发电机表达式与产量表示没有区别。 然而，从我可以看到使用收益将产生回到for循环每次发生器表达式不。 它完成它的任务，然后返回for循环。 这可能是一个在内存使用（取决于你正在循环）正确的相当大的差异？ 我在想我吗？ # ge
I have a question regarding converting a yield statement to a generator expression So I have this small yield method that gets a function and a starting number as its inputs, and basically calls the function for each previous number that was called ie: The first call returns the initial number The second call returns the function(initial number) The third call returns the function(second
我有一个关于将yield语句转换为生成器表达式的问题 所以我有这样一个小的yield方法，它得到一个函数和一个起始号作为它的输入，并且基本上为每个之前被称为ie的数字调用函数： 第一次通话返回初始号码 第二次调用返回函数（初始数字） 第三个调用返回该函数（第二个数字） 第四次呼叫返回功能（第三个号码） 等等。这里是Python中的代码： def some_func(function, number): while True: yield number
I know that yield turns a function into a generator, but what is the return value of the yield expression itself? For example: def whizbang(): for i in range(10): x = yield i What is the value of variable x as this function executes? I've read the Python documentation: http://docs.python.org/reference/simple_stmts.html#grammar-token-yield_stmt and there seems to be no menti
我知道yield会将函数转换为生成器，但yield表达式本身的返回值是多少？ 例如： def whizbang(): for i in range(10): x = yield i 该函数执行时变量x的值是多少？ 我读过Python文档：http：//docs.python.org/reference/simple_stmts.html#grammar-token-yield_stmt，似乎没有提到yield表达式本身的价值。 您也可以send值send给生成器。 如果没有值被发送，那么x是None ，否则x将发送值。 以下是一些信息
according to answer to this question, yield break in C# is equivalent to return in python. in normal case, 'return' indeed stop a generator. But if your function does nothing but return, you will get a None not an empty iterator, which is returned by yield break in C# def generate_nothing(): return for i in generate_nothing(): print i you will get a TypeError: 'NoneType&#
根据对这个问题的回答，C＃中的yield break与python中的return相当。 在正常情况下，'返回'的确停止了发电机。 但是，如果你的函数什么都不做，只能返回，你将得到一个None，而不是一个空的迭代器，它是由C＃中的yield break返回的。 def generate_nothing(): return for i in generate_nothing(): print i 你将得到一个TypeError：'NoneType'对象不可迭代。 但是如果我在返回之前添加一个永不退
I've read What are Class methods in Python for? but the examples in that post are complex. I am looking for a clear, simple, bare-bones example of a particular use case for classmethods in Python. Can you name a small, specific example use case where a Python classmethod would be the right tool for the job? 初始化的辅助方法： class MyStream(object): @classmethod def from_file(cl
我读过Python中的什么是类方法？ 但该帖子中的例子很复杂。 我正在寻找Python中类方法的特定用例的清晰，简单，简单的示例。 你能举出一个小的，具体的示例用例，其中一个Python classmethod将是该工作的正确工具吗？ 初始化的辅助方法： class MyStream(object): @classmethod def from_file(cls, filepath, ignore_comments=False): with open(filepath, 'r') as fileobj: for obj in cl
I'm still learning Python as I want to teach the essential concepts of the language to eleven year old kids (I work as a teacher). We have done a bit of work in basic so they understand the essentials of programming and breaking down tasks into chunks and such like. Python is the language that is going to be taught all across the UK with the new curriculum coming in and I don't want to
我仍然在学习Python，因为我想向十一岁的孩子（我作为一名教师工作）教授这门语言的基本概念。 我们在基础方面做了一些工作，以便他们理解编程的基本要点，并将任务分解为块等。 Python是将要在全英国范围内教授的新语言，新课程即将出台，我不想教孩子们坏习惯。 下面是我写的一个小程序，是的，我知道它很糟糕，但任何关于改进的建议都将非常感激。 我仍在翻阅关于该语言的教程，所以请温和！ ：O） # This sets the con
With the Book: - "Hello World! Computer Programming for Kids and Other Beginners", I want to Start Learn Python, because I am Novice to programming. But the Problem is that this book teach python with 2.5 version, And I want to learn this book with Python 2.6 version, because, side by side, I want to learn 'Google App Engine" & Google recommending Python 2.6 for GAE. Plea
随书： - “Hello World！为孩子们和其他初学者编写计算机编程”， 我想开始学习Python，因为我是编程的新手。 但问题是，这本书教2.5版本的Python， 并且我想用Python 2.6版本学习本书，因为我想学习'Google App Engine'并且Google推荐Python 2.6 for GAE。请告诉那本书是否可以学习Python 2.6？ 如果你是一个新手，寻找一本好的开始Python书，我会建议看看学习Python的艰难之路 对于Python 2.6，您最好使用本书。 这