Writing to module

Lets say I have these 3 (tiny) python files - a.py myvar = 'a' b.py import a import c myvar = 'b' c.pr() c.py from a import myvar def pr(): print myvar Now if I execute b.py I get output a But I really want output to be as b So please tell me how can I restructure/modify the programs so that the module-wide myvar can be assigned a different value. In b.py , you are setting b.p

写入模块

可以说我有这3个(小)python文件 - a.py myvar = 'a' b.py import a import c myvar = 'b' c.pr() c.py from a import myvar def pr(): print myvar 现在,如果我执行b.py我会得到输出 a 但我真的想要输出为 b 所以请告诉我如何重构/修改程序,以便为模块范围的myvar分配不同的值。 在b.py中 ,您正在设置b.py的myvar。 你想访问myvar的值。 所以b.py可能看起来像: import a import c a.myvar = 'b' #

how to access attributes initialized in class constructor of different py file?

I have two py files. a.py and b.py inside a package called test (has __init__.py ) and I want to access attribute self.items defined in the a.py below import b class Window(object): def __init__(self): self.items={'Magenta':'mag','Grey':'gre','Red':'red'} def getMats(): newobj=b.BAR() selected = newobj.type_of_mats[1] from a different py file b.py[below] so i

如何访问在不同py文件的类构造函数中初始化的属性?

我有两个py文件。 名为test的包内有a.py和b.py(有__init__.py ) 我想访问下面a.py中定义的属性self.items import b class Window(object): def __init__(self): self.items={'Magenta':'mag','Grey':'gre','Red':'red'} def getMats(): newobj=b.BAR() selected = newobj.type_of_mats[1] 从一个不同的py文件b.py [下],所以在b.py我导入了一个模块,即 import a #now obj = a.Windo

Python: read and execute lines from other script (or copy them in)?

Consider a python script: #### #Do some stuff# #### #Do stuff from separate file #### #Do other stuff What it the best way to implement the middle bit (do stuff that is defined in another file)? I've been told that in C++ there's a command that can achieve what I'm looking to do. Is there an equivalent in Python? eg if A.py is: print 'a' ### import contents of other file her

Python:从其他脚本读取和执行行(或复制它们)?

考虑一下python脚本: #### #Do some stuff# #### #Do stuff from separate file #### #Do other stuff 什么是最好的方式来实现中间位(做在另一个文件中定义的东西)? 我被告知在C ++中有一个命令可以实现我期待的目标。 Python中是否有等价物? 例如,如果A.py是: print 'a' ### import contents of other file here print 'm' 和B.py是: print 'b' print 'c' print 'd' 那么A.py的期望输出是: a b c d m

How does import keyword in python actually work?

Let's say I have 3 files: a.py from d import d class a: def type(self): return "a" def test(self): try: x = b() except: print "EXCEPT IN A" from b import b x = b() return x.type() b.py import sys class b: def __init__(self): if "a" not in sys.modules: print "Importing a!"

Python中的import关键字如何工作?

假设我有3个文件: a.py from d import d class a: def type(self): return "a" def test(self): try: x = b() except: print "EXCEPT IN A" from b import b x = b() return x.type() b.py import sys class b: def __init__(self): if "a" not in sys.modules: print "Importing a!" fro

Why does this multiprocessing code fail?

This question already has an answer here: Why does Python's multiprocessing module import __main__ when starting a new process on Windows? 1 answer When you create a new child process, the child process might (mostly depending on the OS you are using) re-import the current module. In your case, re-importing the module also executes these two lines: Process(target=sample).start() Proce

为什么这个多处理代码失败?

这个问题在这里已经有了答案: 为什么在Windows上启动新进程时,Python的多处理模块会导入__main__? 1个答案 当您创建新的子进程时,子进程可能(主要取决于您正在使用的操作系统)重新导入当前模块。 在你的情况下,重新导入模块也执行这两行: Process(target=sample).start() Process(target=sample).start() 会发生什么,错误消息告诉你什么: 在当前进程完成引导阶段之前,已尝试开始一个新进程。 这可能意味

super(type, object

class B1(object): def f(self): print "B1.f" class B2(object): def f(self): print "B2.f" class D(B1, B2): pass d = D() super(B1, d).f() print B1.__mro__ Why does the above code print: B2.f (<class '__main__.B1'>, <type 'object'>) whereas the documentation http://docs.python.org/2/library/functions.html#super

超级(类型,对象

class B1(object): def f(self): print "B1.f" class B2(object): def f(self): print "B2.f" class D(B1, B2): pass d = D() super(B1, d).f() print B1.__mro__ 为什么要打印上面的代码: B2.f (<class '__main__.B1'>, <type 'object'>) 而文档http://docs.python.org/2/library/functions.html#super说: super(type[, object

Clear terminal in Python

是否存在任何标准的“附带电池”方法来清除Python脚本中的终端屏幕,还是必须去诅咒(图书馆,而不是词)? 关于转义序列呢? print(chr(27) + "[2J") A simple and cross-platform solution would be to use either the cls command on Windows, or clear on Unix systems. Used with os.system , this makes a nice one-liner: import os os.system('cls' if os.name == 'nt' else 'clear') Why hasn't anyone talked abou

在Python中清除终端

是否存在任何标准的“附带电池”方法来清除Python脚本中的终端屏幕,还是必须去诅咒(图书馆,而不是词)? 关于转义序列呢? print(chr(27) + "[2J") 一个简单的和跨平台的解决方案是请使用cls在Windows命令,或clear在Unix系统。 与os.system一起os.system ,这是一个很好的一行代码: import os os.system('cls' if os.name == 'nt' else 'clear') 为什么没有人只是简单地做Ctrl + L。 无疑是最简单的清除屏幕的方法。

PySide Qt Creator message dialog exit

So I created a ui file with Qt Creator that has, among other things, a QPushButton. Just for testing purposes I want to pop up a QMessageDialog that says hello! After opening the ui in the main window class, I connect the button from the ui to the def hello(self): myWidget.helloButton.clicked.connect(self.hello) then later on def hello(self): QtGui.QMessageBox.question(self,'Message',"he

PySide Qt Creator消息对话框退出

所以我用Qt Creator创建了一个包含QPushButton的ui文件。 只是为了测试的目的,我想弹出一个QMessageDialog,声明你好! 在主窗口类中打开ui之后,我将ui的按钮连接到def hello(self): myWidget.helloButton.clicked.connect(self.hello) 然后再 def hello(self): QtGui.QMessageBox.question(self,'Message',"hello!",QtGui.QMessageBox.Ok) 消息弹出“你好!” 在消息对话框中单击“确定”后,整个python程序退出,

What exactly are iterator, iterable, and iteration?

What are the most basic definitions of "iterable", "iterator" and "iteration in Python? I've read multiple definitions but their exact meaning still won't sink in. Can someone please help me with the basic idea? Iteration is a general term for taking each item of something, one after another. Any time you use a loop, explicit or implicit, to go over a group

迭代器,迭代器和迭代究竟是什么?

“iterable”,“iterator”和“Python中的迭代”最基本的定义是什么? 我已经阅读了多个定义,但其确切含义仍然不会沉入其中。 有人可以帮助我的基本想法吗? 迭代是一个接一个地接受每件事物的总称。 任何时候你使用循环,显式或隐式,遍历一组项目,这是迭代。 在Python中, iterable和iterator具有特定的含义。 iterable是一个具有__iter__方法的对象,该方法返回一个迭代器 ,或者定义一个可以从零开始的连续索引的__g

Daemon Threads Explanation

In the Python documentation it says: A thread can be flagged as a "daemon thread". The significance of this flag is that the entire Python program exits when only daemon threads are left. The initial value is inherited from the creating thread. Does anyone have a clearer explanation of what that means or a practical example showing where you would want to set threads as daemonic ?

守护线程说明

在Python文档中它说: 线程可以被标记为“守护线程”。 这个标志的意义在于,只有守护进程线程退出时,整个Python程序才会退出。 初始值是从创建线程继承的。 有没有人对这意味着什么或者一个实际的例子有更清楚的解释,说明你想把线程设置为daemonic ? 为我澄清: 所以你唯一不会把线程设置为守护进程的是,如果你希望它们在主线程退出后继续运行, 一些线程执行后台任务,例如发送Keepalive数据包,或执行定期垃圾