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…

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…

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…

syncookies cookies the connection state,when the ack arrives,then deal with the pause connection,very wise mind --------------------------------------------------------------------------- seems to be enough -------------------------------------------…

#-*- coding: UTF-8 -*- class Solution(object):       def canConstruct(self, ransomNote, magazine):        ransomNote=list(ransomNote)        magezine=list(magazine)                for ransom in ransomNote:            if(magezine.__contains__(ransom))…

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. 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.…

原文:http://www.jianshu.com/p/94516a58314d Dataset transformations| 数据转换 Combining estimators|组合学习器 Feature extration|特征提取 Preprocessing data|数据预处理 1 Dataset transformations scikit-learn provides a library of transformers, which may clean (see Preproce…

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…

Code Like a Pythonista: Idiomatic Python David Goodger goodger@python.org http://python.net/~goodger In this interactive tutorial, we'll cover many essential Python idioms and techniques in depth, adding immediately useful tools to your belt. There a…

Symptom You have questions related to the SAP HANA memory. You experience a high memory utilization or out of memory dumps. Environment SAP HANA Cause 1. Which indications exist for SAP HANA memory problems?2. How can I collect information about the…

Why Python is Slow: Looking Under the Hood https://jakevdp.github.io/blog/2014/05/09/why-python-is-slow/ MAY 09, 2014 We've all heard it before: Python is slow. When I teach courses on Python for scientific computing, I make this point very early in…

How to compile pycrypto 2.4.1 (python 3.2.2 for Windows 7 x64) Nov 10 Posted by alesk This note is a variation of note that talks about compiling cx_Oracle module for python 3.2 (64-bit), but this time around I wanted to try out pycrypto module v2.4.…

0.目录 2. 术语 global interpreter lock 全局解释器锁3. C-API 还有更多没有仔细看4. 定期切换线程5. wiki.python6. python.doc FAQ 1.参考 2. 术语 global interpreter lock 全局解释器锁 https://docs.python.org/2/glossary.html#term-global-interpreter-lock https://docs.python.org/3/glossary.html…

"""HMAC (Keyed-Hashing for Message Authentication) Python module. Implements the HMAC algorithm as described by RFC 2104. """ import warnings as _warnings from _operator import _compare_digest as compare_digest import hashlib…

第04章:字典 当索引不好用时 Python唯一的内建的映射类型,无序,但都存储在一个特定的键中.键能够使字符.数字.或者是元祖. ------ 字典使用: 表征游戏棋盘的状态,每一个键都是由坐标值组成的元祖 存储文件改动的次数,文件名称作为键 数字电话/地址薄 函数传递值def func(x,*args,**args): 假设要建公司员工与座机号的列表,假设要获得Alice的座机仅仅能这么找 >>> names   = ['Alice','Bob','Tom'] >>>…

python拓展包安装 直接安装拓展包默认路径: Unix(Linux)默认路径:/usr/local/lib/pythonX.Y/site-packagesWindows默认路径:C:\PythonXY\Lib\site-packages 测试和升级python拓展安装包pip 查看pip安装时对应的Python版本 which pip /d/python3.4.2/Scripts/pip 更新pip: python -m pip install --upgrade pip 测试python拓…

遍历字典 1. 遍历所有键值对 eg1: user_0 = { 'username': 'efermi', 'first': 'enrico', 'last': 'fermi',}for key, value in user_0.items(): print("\nKey: " + key) print("Value: " + value) for key, value in user_0.items(): 也可简化为 for k, v in user_0.item…

目录 目录 模块的搜索路径和路径搜索 搜索路径 命名空间和变量作用域的比较 变量名的查找覆盖 导入模块 import 语句 from-import 语句 扩展的 import 语句 as 自动载入模块 模块导入的特性 模块内建函数 __import__ globals locals reload Package 包 __init__py import package 模块的搜索路径和路径搜索 搜索路径 默认的模块搜索路径在 Python 解析器编译安装时被指定, 我们可以通过 sys 模块来查看…

当你的Flask项目通过Nginx+uWSGI成功部署的时候,当你很高兴你Flask里面的接口成功跑通的时候,你会发现真高兴!好牛逼! 然后当你写了其他几个接口的时候,在启动uWSGI服务的时候,死活报错,而且你从网上还找不到相关的方法时,找到能用的方法都试了,都不行,你会发现卧槽,真烦! 我就是如同做了过山车一般,体会了全过程!话不多说,摆出问题,解决问题! 当你成功启动uWSGI服务时: 我的需求是将服务器中目录里面的图片,通过zipfile函数借助BytesIO()一次性打包,下载到本地;…

PIP & Python packages management $ python3 --version # OR $ python3 -V # Python 3.7.3 $ pip --version # pip 18.1 from /Users/xgqfrms-mbp/anaconda3/lib/python3.7/site-packages/pip (python 3.7) ➜ ~ Note: If you have Python version 3.4 or later, PIP is…

Apache Spark 2.2.0 中文文档 - 快速入门 | ApacheCN Geekhoo 关注 2017.09.20 13:55* 字数 2062 阅读 13评论 0喜欢 1 快速入门 使用 Spark Shell 进行交互式分析 基础 Dataset 上的更多操作 缓存 独立的应用 快速跳转 本教程提供了如何使用 Spark 的快速入门介绍.首先通过运行 Spark 交互式的 shell(在 Python 或 Scala 中)来介绍 API, 然后展示如何使用 Java , Scal…

It shows how to use RBFSampler and Nystroem to approximate the feature map of an RBF kernel for classification with an SVM on the digits dataset. Results using a linear SVM in the original space, a linear SVM using the approximate mappings and using…

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…