我之前写了一篇关于Python参数传递(http://www.cnblogs.com/lxw0109/p/python_parameter_passing.html)的博客, 写完之后,我发现我在使用list的时候(我想在函数中改变实参),感觉使用文章中提到的传参理解还是有点儿迷惑和混乱 所以在此关于list的参数传递,再做一下补充和说明,这些是我个人的理解,如果您感觉有任何疑问或者不同的观点,非常 感谢您与我讨论,谢谢. #!/usr/bin/python #coding:utf-8 #Fil…

我刚刚开始学习Python, Python中的参数传递总是让我很困惑.我写了4个简单的Demo,帮助我理解Python的参数传递,希望对大家都能有所帮助. 0: def change(x): x = 1 a = 10print('a is {0}'.format(a)) change(a) print('a is {0}'.format(a)) Output:a is 10a is 10 1: def change1(x): x = [1, 2] a = [10, 20]print('a is…

Python’s handling of default parameter values is one of a few things that tends to trip up most new Python programmers (but usually only once). What causes the confusion is the behaviour you get when you use a “mutable” object as a default value; tha…

This Blog is a compilation of various methods of passing Request Parameters in JSF (2.0 +) (1)  f:viewParam One of the features added in JSF 2.0 is "View Parameters"; Simply speaking it allows adding "Query string" or "Request Par…

package main import ( "fmt" ) func main() { fmt.Println("Hello, playground") var str string = "1241341" fmt.Println(&str) fmt.Println(MyString(str)) m := map[string]string {"A": "A"} fmt.Printf("m…

1. Variables Are Not Boxes # Think variables as sticky notes a = [1, 2, 3] b = a a.append(4) print b # [1, 2, 3, 4] # 1. The object is created before the assignment. So variable is # assigned to an object, not the other way around. 2. Identity, Equal…

1. get files in the current directory with the assum that the directory is like this: a .py |----dataFolder |----Myfolder |----1.csv , 2.csv, 3.csv # a.py 1 def getFileList(): file_list = [] cur_dir = os.getcwd() for folder in os.walk(cur_dir).next()…

So if you are looking forward to a Python Interview, here are some most probable questions to be asked in the interview that will help: What is the difference between deep and shallow copy? Write a program to find out the name of an object in python.…

本文将介绍使用mutable对象作为Python函数参数默认值潜在的危害,以及其实现原理和设计目的 本博客已经迁移至: http://cenalulu.github.io/ 本篇博文已经迁移,阅读全文请点击: http://cenalulu.github.io/python/default-mutable-arguments/ 陷阱重现 我们就用实际的举例来演示我们今天所要讨论的主要内容. 下面一段代码定义了一个名为generate_new_list_with的函数.该函数的本意是在每次调用时都…

这里我们看看Python中函数定义的语法,函数的局部变量,函数的参数,Python中函数的形参可以有默认值,参数的传递是赋值操作,在函数调用时,可以对实参进行打包和解包  1,函数定义 关键字def引出函数定义,后面跟着函数名以及用括号括起来的一系列参数,然后从下一行开始函数体(function body),并且要缩进. 生成一个Fibnacci数列的序列,最大不超过某个数的函数 def fib(n): '''get a list of fibnacci series to n''' a, b…

原文:Simple Tutorial on SVM and Parameter Tuning in Python and R 介绍 数据在机器学习中是重要的一种任务,支持向量机(SVM)在模式分类和非线性回归问题中有着广泛的应用. SVM最开始是由N. Vapnik and Alexey Ya. Chervonenkis 在1963年提出.从那时候开始,各种支持向量机被成功用于解决各种现实问题,比如文本聚类,图像分类,生物信息学(蛋白质分类,爱长分类),手写字符识别等等. 内容 1. 什么是支持…

请看如下一段程序: def extend_list(v, li=[]): li.append(v) return li list1 = extend_list(10) list2 = extend_list(123, []) list3 = extend_list('a') print(list1) print(list2) print(list3) print(list1 is list3) 请先猜想打印的结果: 是不是这样: [10] [123] [a] False 但是,实际的打印效果 请…

一个老问题: def func(defau=[]): defau.append(1) return defau print(func())#print[1] print(func())#print[1,1] print(func())#print[1,1,1] 学python时候应该都遇到过这个问题,为什么?一般的说法是把这个可变的默认参数和函数绑定在一块了 但是,怎么绑定的??? 看python文档[1],里面对def的解释: A function definition is an execu…

add by zhj: 在Python文档中清楚的说明了默认参数是怎么工作的,如下 "Default parameter values are evaluated when the function definition is executed. This means that the expression is evaluated once, when the function is defined, and that the same “pre-computed” value is used…

1. Introduction. 1.1 In part 1 of this series of blogs we studied how to pass a managed structure (which contains strings) to unmanaged code. The structure was passed as an "in" (by-value) parameter, i.e. the structure was passed to the unmanage…

1. Introduction. 1.1 In part 1 of this series of blogs we studied how to pass a managed structure (which contains strings) to unmanaged code. The structure was passed as an "in" (by-value) parameter, i.e. the structure was passed to the unmanage…

本文转自:http://xianglong.me/article/how-to-code-like-a-pythonista-idiomatic-python 最近在网上看到一篇介绍Pythonic编程的文章:Code Like a Pythonista: Idiomatic Python,其实作者在2006的PyCon会议后就写了这篇文章,写这篇文章的主要原因是作者发现很多有经验的Pythoner写出的代码不够Pythonic.我觉得这篇文章很不错,所以将它用中文写了下来(不是逐字的翻译,中间…

转自:http://www.liuhaihua.cn/archives/23475.html Harries 发布于 7天前 分类:编程技术 阅读(15) 评论(0) 最近在网上看到一篇介绍Pythonic编程的文章: Code Like a Pythonista: Idiomatic Python ,其实作者在2006的PyCon会议后就写了这篇文章,写这篇文章的主要原因是作者发现很多有经验的Pythoner写出的代码不够Pythonic.我觉得这篇文章很不错,所以将它用中文写了下来(不是逐字…

The head is empty and empty. Just practicing English will not have any effect. The best effect is to practice English thinking and systematic thinking. Yesterday's study a lot, let's review, have appetizers, use python interpreter, parameter passing,…

原文:https://docs.python.org/3/library/inspect.html 中文:https://www.rddoc.com/doc/Python/3.6.0/zh/library/inspect/?highlight=inspect 关于python中inspect模块的一些探究----------https://blog.csdn.net/weixin_35955795/article/details/53053762 The inspect module provi…

http://perugini.cps.udayton.edu/teaching/courses/Spring2015/cps352/index.html#lecturenotes Programming Languages: Chapter 1: Introduction Programming languages Some fundamental questions what is a language? a medium of communication what is a program…

本笔记记录自 Coursera课程 <计算机程式设计> 台湾大学 刘邦锋老师 Week4 Functions 4-1 System Function 函数主要分为两大类系统定义函数与使用者定义函数,例如printf和main. 例子:(sys-function.c)呼叫系统定义函数 #include <stdio.h> /* for printf and scanf */ #include <stdlib.h> /* for abs */ #include <ma…

va_list深究 2011-04-21 21:06:11|  分类: C/C++|字号 订阅     VA函数(variable argument function),参数个数可变函数,又称可变参数函数.C/C++编程中,系统提供给编程人员的va函数很少.*printf()/*scanf()系列函数,用于输入输出时格式化字符串:exec*()系列函数,用于在程序中执行外部文件(main(int argc, char* argv[]算不算呢,与其说main()也是一个可变参数函数,倒不如说它是e…

A recently implemented enhanced wildcard string matcher, features of which including, Supporting wildcard character '*' for matching zero or more characters Supporting wildcard character '?' for matching exactly one character Supporting parentheses '…

1.第一次感觉MS也有这么难用的MFC类: 2.CFtpFileFind类只能实例化一个,多个实例同时查找会出错(因此下载时不能递归),采用队列存储目录再依次下载: 3.本程序支持文件夹嵌套上传下载: 4.boost::filesystem::create_directory不能递归创建文件夹,需手动实现 5.同时支持文件夹先打包压缩再上传功能(m_bZibFlag控制是否压缩) 代码如下: CFtpClient.h #ifndef __ftp_client_h__ #define __ftp_…

转载:http://blogs.embarcadero.com/jimtierney/2009/04/06/31461/ DataSnap Server Method Stream Parameters This is a continuation of my posts on DataSnap server method parameters and return types.  This post is about  TStream and TDBXStreamValue.    The s…

4.5. Method ParametersLet us review the computer science terms that describe how parameters can be passed to a method (or a function) in a programming language. The term call by value(值调用) means that the method gets just the value that the caller pro…

随着64位操作系统的普及,都开始大力进军x64,X64下的调试机制也发生了改变,与x86相比,添加了许多自己的新特性,之前学习了Windows x64的调试机制,这里本着“拿来主义”的原则与大家分享. 本文属于译文,英文原文链接:http://www.codemachine.com/article_x64deepdive.html 翻译原文地址:深入Windows X64 调试 在正式开始这篇译文之前,译者先定义下面两个关于栈帧的翻译: frame pointer:栈帧寄存器.栈帧指针,在X86…

Interfacing C to Assembler You can easily interface your C programs to routines written in XC16x/C16x/ST10 assembly language. The A166 Assembler is a macro assembler that emits object modules in OMF166 format. By following a few programming rules, yo…

RenderScript RenderScript is a framework for running computationally intensive tasks at high performance on Android. RenderScript is primarily oriented for use with data-parallel computation, although serial computationally intensive workloads can be…