Python and Java parameter passing

This question already has an answer here: How do I pass a variable by reference? 23 answers Yes Python seems to be equivalent to Java in this respect. From http://learnpython.pbworks.com/w/page/15956522/Assignment : But you must be careful about what is meant by "changes to parameters". Assigning a new value to a parameter name (inside the function, a parameter is just a local

Python和Java参数传递

这个问题在这里已经有了答案: 如何通过引用传递变量? 23个答案 是的,Python在这方面似乎等同于Java。 来自http://learnpython.pbworks.com/w/page/15956522/Assignment: 但是,您必须小心“参数更改”的含义。 为参数名称(在函数内部,一个参数只是一个局部变量)赋值一个新值不会改变原始对象 - 它只会将局部变量重新绑定到一个新对象。 所以,Python通过“值”传递“对象引用”。

Incrementing integer variable of global scope in Python

This question already has an answer here: How do I pass a variable by reference? 23 answers Because x is a local (all function arguments are), not a global, and integers are not mutable. So x += 1 is the same as x = x + 1 , producing a new integer object, and x is rebound to that. You can mark x a global in the function: def add_one(): global x x += 1 There is no point in passi

在Python中增加全局作用域的整数变量

这个问题在这里已经有了答案: 如何通过引用传递变量? 23个答案 因为x是局部的(所有函数参数都是),而不是全局的,整数不可变。 所以x += 1与x = x + 1 ,产生一个新的整数对象,并且x反弹回来。 您可以在函数中将x标记为全局: def add_one(): global x x += 1 在这里传递x作为参数没有意义。

Python: Reassign value to variable (using a function)

Possible Duplicate: Python: How do I pass a variable by reference? How can I reassign a value to a variable that is passed as a function argument? For instance, what I am looking to do is: foo = True def convert(foo): if foo == True: foo = 'on' elif foo == False: foo = 'off' return foo where foo is now a string. The problem with the method above is that in or

Python:重新赋值给变量(使用函数)

可能重复: Python:我如何通过引用传递变量? 我如何重新分配一个值作为函数参数传递的变量? 例如,我期待的是: foo = True def convert(foo): if foo == True: foo = 'on' elif foo == False: foo = 'off' return foo foo现在是一个字符串。 上述方法的问题是,为了将foo从布尔类型更改为字符串类型,必须传递以下内容: foo = convert(foo) 而我正在寻找像这样的东西: convert(fo

Python : When is a variable passed by reference and when by value?

Possible Duplicate: Python: How do I pass a variable by reference? My code : locs = [ [1], [2] ] for loc in locs: loc = [] print locs # prints => [ [1], [2] ] Why is loc not reference of elements of locs ? Python : Everything is passed as reference unless explicitly copied [ Is this not True ? ] Please explain.. how does python decides referencing and copying ? Update : How

Python:什么时候通过引用传递变量,何时传值?

可能重复: Python:我如何通过引用传递变量? 我的代码: locs = [ [1], [2] ] for loc in locs: loc = [] print locs # prints => [ [1], [2] ] 为什么loc没有引用的元素locs ? Python:一切都作为参考传递,除非明确复制[这是不是真的? ] 请解释一下.. python如何决定引用和复制 ? 更新: 怎么做 ? def compute(ob): if isinstance(ob,list): return process_list(ob) if isinstance(ob,dic

stream not terminated after firefox disconnects

I am trying to create a Flask server that streams data to the client using sse. The piece of test-code below seems to do the trick, but I stumbled upon a problem related to handling client disconnects. When using Firefox as the client (versions 28 or 29), data starts streaming as expected. However, when I reload the page, a new stream is opened (as expected) but the old stream still remains.

流在firefox断开连接后没有终止

我正在尝试创建一个使用sse将数据传输到客户端的Flask服务器。 下面这段测试代码似乎可以解决问题,但我偶然发现了一个与处理客户端断开连接有关的问题。 当使用Firefox作为客户端(版本28或29)时,数据按预期开始流式传输。 但是,当我重新加载页面时,会打开一个新流(如预期的那样),但旧流仍然存在。 处理流的eventgen()线程永远不会终止。 在其他客户端(我使用Yaffle的Polyfill EventSource实现以及Chrome尝试IE

Capturing output of subprocess.Popen() with nose

I'm using nose to test an application that uses subprocess.Popen() to call a script. Neither the capture or logcapture plugin seem to capture the output of this script. Is there an easy way to pipe this output to nose? Here's what I've attempted so far; note "Capture me" isn't captured: example.py : if __name__ == '__main__': print 'Capture me' test.py : im

用鼻子捕获subprocess.Popen()的输出

我使用nose来测试使用subprocess.Popen()调用脚本的应用程序。 捕获或logcapture插件似乎不捕获此脚本的输出。 有没有一种简单的方法可以将此输出管道传输至鼻子? 这是我到目前为止的尝试; 注意不捕获“捕获我”: example.py : if __name__ == '__main__': print 'Capture me' test.py : import subprocess import sys def test_popen(): # nose's capture plugin replaces sys.stdout with a StringIO ins

Why is the Python readline module not available on OS X?

The documentation of the Python readline module says "Availability: Unix". However, it doesn't appear to be available on OS X, although other modules marked as Unix are available. Here is what I'm using: $ uname -a Darwin greg.local 8.11.1 Darwin Kernel Version 8.11.1: Wed Oct 10 18:23:28 PDT 2007; root:xnu-792.25.20~1/RELEASE_I386 i386 i386 $ which python /usr/bin/python $

为什么Python readline模块在OS X上不可用?

Python readline模块的文档说“可用性:Unix”。 但是,尽管其他标记为Unix的模块可用,但OS X似乎不可用。 以下是我正在使用的内容: $ uname -a Darwin greg.local 8.11.1 Darwin Kernel Version 8.11.1: Wed Oct 10 18:23:28 PDT 2007; root:xnu-792.25.20~1/RELEASE_I386 i386 i386 $ which python /usr/bin/python $ python Python 2.3.5 (#1, Nov 26 2007, 09:16:55) [GCC 4.0.1 (Apple Computer, Inc. build 5363) (+48

Python word counter

I'm taking a Python 2.7 course at school, and they told us to create the following program: Assume s is a string of lower case characters. Write a program that prints the longest substring of s in which the letters occur in alphabetical order. For example, if s = azcbobobegghakl , then your program should print Longest substring in alphabetical order is: beggh In the case of ties, p

Python字计数器

我在学校学习Python 2.7课程,他们告诉我们要创建以下程序: 假定s是一串小写字符。 编写一个程序,以字母顺序打印s中最长的子字符串。 例如,如果s = azcbobobegghakl,那么你的程序应该打印 字母顺序中最长的子字符串是:beggh 在关系的情况下,打印第一个子字符串。 例如,如果s ='abcbcd',那么你的程序应该打印 字母顺序中最长的子字符串是:abc 我写了下面的代码: s = 'czqriqfsqteavw' string

Why doesn't Python have multiline comments?

OK, I'm aware that triple-quotes strings can serve as multiline comments. For example, """Hello, I am a multiline comment""" and '''Hello, I am a multiline comment''' But technically speaking these are strings, correct? I've googled and read the Python style guide, but I was unable to find a technical answer to why there is no formal implementation of multiline, /* */ type

为什么Python没有多行注释?

好的,我知道三重引号字符串可以用作多行注释。 例如, """Hello, I am a multiline comment""" 和 '''Hello, I am a multiline comment''' 但从技术上讲,这些都是字符串,对吗? 我搜索了一下并阅读了Python风格指南,但是我无法找到技术答案,为什么没有正式实现多行,/ * * /类型的评论。 使用三重引号我没有问题,但对于导致此设计决定的原因,我有点好奇。 我怀疑你会得到比这更好的答案,“Guido觉得不

Integration Testing Multiple Celery Workers and a DB Backed Django API

I'm working with a Software Oriented Architecture that has multiple celery workers (let's call them worker1 , worker2 , and worker3 ). All three workers are separate entities (ie, separate code bases, separate repos, separate celery instances, separate machines) and none of them are connected to a Django app. Communicating with each of these three workers is a Django based, MySQL backe

集成测试多个Celery Workers和一个DB支持的Django API

我正在使用一个有多个芹菜工作者的软件定向架构(我们称之为worker1 , worker2和worker3 )。 所有这三个工作人员都是独立的实体(即独立的代码库,独立的仓库,独立的芹菜实例,独立的机器),并且它们都不连接到Django应用程序。 与这三个工作人员进行通信的是基于Django的MySQL支持的RESTful API。 在开发过程中,这些服务都是在一个无用的盒子上,每个服务器都作为一个单独的机器运行,从一个单独的端口运行。 我们有