From 690324d4a9f5c52a76c680f018355e675100db8e Mon Sep 17 00:00:00 2001 From: zhengsihua Date: Fri, 19 Dec 2014 22:40:23 +0800 Subject: [PATCH] translated --- ...irst App on Linux with Python and Flask.md | 210 ------------------ ...irst App on Linux with Python and Flask.md | 208 +++++++++++++++++ 2 files changed, 208 insertions(+), 210 deletions(-) delete mode 100644 sources/tech/20141219 Creating your First App on Linux with Python and Flask.md create mode 100644 translated/tech/20141219 Creating your First App on Linux with Python and Flask.md diff --git a/sources/tech/20141219 Creating your First App on Linux with Python and Flask.md b/sources/tech/20141219 Creating your First App on Linux with Python and Flask.md deleted file mode 100644 index 61c01d4368..0000000000 --- a/sources/tech/20141219 Creating your First App on Linux with Python and Flask.md +++ /dev/null @@ -1,210 +0,0 @@ -Translating-----geekpi - -Creating your First App on Linux with Python and Flask -================================================================================ -![](http://techarena51.com/wp-content/uploads/2014/12/python-logo.png) - -Whether playing on Linux or working on Linux there is high chance you have come across a program written in python. Back in college I wish they thought us Python instead of Java like they do today, it’s fun to learn and useful in building practical applications like the yum package manager. - -In this tutorial I will take you through how I built a simple application which displays useful information like [memory usage per process][1], CPU percentage etc using python and a micro framework called flask. - -### Prerequisites ### - -Python Basics, Lists, Classes, Functions, Modules. -HTML/CSS (basic) - -You don’t need to be an advanced python programmer to follow this tutorial, But before you go further I recommend you read https://wiki.python.org/moin/BeginnersGuide/NonProgrammers - -### Installing Python 3 on Linux ### - -On most Linux distributions python is installed by default. This is how you can find out the python version on your system. - - [root@linux-vps ~]# python -V - Python 2.7.5 - -We will be using python version 3.x to build our app. As per [Python.org][2] all improvements are now only available in this version which is not backward compatible with python 2. - -**Caution**: Before your proceed I strongly recommend you try this tutorial out on a Virtual machine, since python is a core component of many Linux Distributions any accidents may cause permanent damage to your system. - -This step is for RedHat based variants like CentOS (6&7), Debian based variants like Ubuntu,Mint and Rasbian can skip this step as you should have python version 3 installed by default. If not use apt-get instead of yum to install the relevant packages below. - - [leo@linux-vps] yum groupinstall 'Development Tools' - [leo@linux-vps] yum install -y zlib-dev openssl-devel sqlite-devel bzip2-devel - [leo@linux-vps] wget https://www.python.org/ftp/python/3.4.2/Python-3.4.2.tgz - [leo@linux-vps] tar -xvzf Python-3.4.2.tgz - [leo@linux-vps] cd Python-3.4.2 - [leo@linux-vps] ./configure - [leo@linux-vps] make - # make altinstall is recommended as make install can overwrite the current python binary, - [leo@linux-vps] make altinstall - -After a successful, installation you should be able to access the python 3.4 shell with the command below. - - [leo@linux-vps]# python3.4 - Python 3.4.2 (default, Dec 12 2014, 08:01:15) - [GCC 4.8.2 20140120 (Red Hat 4.8.2-16)] on linux - Type "help", "copyright", "credits" or "license" for more information. - >>> exit () - -### Installing packages in python with PIP ### - -Python comes with it’s own package manager, similar to yum and apt-get. You will need to use it to download, install and uninstall packages. - - [leo@linux-vps] pip3.4 install "packagename" - - [leo@linux-vps] pip3.4 list - - [leo@linux-vps] pip3.4 uninstall "packagename" - -### Python Virtual Environment ### - -In Python a virtual environment is a directory where your projects dependencies are installed. This is a good way to segregate projects with different dependencies. It also allows you to install packages without the need for sudo access. - - [leo@linux-vps] mkdir python3.4-flask - [leo@linux-vps] cd python3.4-flask - [leo@linux-vps python3.4-flask] pyvenv-3.4 venv - -To create the virtual environment you will need to use the “pyvenv-3.4” command. This will create a directory called “lib” inside the venv folder where the dependencies for this project will be installed. It will also create a bin folder which will contain pip and python executables for this virtual environment. - -### Activating the Virtual Environment for our Linux system information project ### - - [leo@linux-vps python3.4-flask] source venv/bin/activate - [leo@linux-vps python3.4-flask] which pip3.4 - ~/python3.4-flask/venv/bin/pip3.4 - [leo@linux-vps python3.4-flask] which python3.4 - ~/python3.4-flask/venv/bin/python3.4 - -### Installing flask with PIP ### - -Lets go ahead and install out first module the flask framework which will take care of the routing and template rendering of our app. - - [leo@linux-vps python3.4-flask]pip3.4 install flask - -### Creating your first app in flask. ### - -Step 1:Create directories where your app will reside. - - [leo@linux-vps python3.4-flask] mkdir app - [leo@linux-vps python3.4-flask]mkdir app/static - [leo@linux-vps python3.4-flask]mkdir app/templates - -Inside the python3.4-flask folder create a folder called app which will contain two sub-folders “static” and “templates”. Our python script will reside inside the app folder, files like css/js inside the static folder and templates folder will contain our html templates. - -Step 2:Create an initialization file inside the app folder. - - [leo@linux-vps python3.4-flask] vim app/_init_.py - from flask import Flask - - app = Flask(__name__) - from app import index - -This file will create a new instance of Flask and load our python program stored in a file called index.py which we will create next. - - [leo@linux-vps python3.4-flask]vim app/index.py - from app import app - - @app.route('/') - def index(): - import subprocess - cmd = subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) - out,error = cmd.communicate() - memory = out.splitlines() - - return - -Routing in flask is handled by the route decorator. It is used to bind a URL to a function. - - @app.route('/') - @app.route('/index') - -In order to run a shell command in python you can use the Popen class from Subprocess module. - - subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) - -This class will take a list as an argument, the first item of the list will default to being executable while the next item will be considered the option. Here is another example - - subprocess.Popen(['ls', ‘-l’],stdout=subprocess.PIPE,stderr=subprocess.PIPE) - -stdout and stderr will store the output and error of this command respectively. You can then access this output via the communicate method of the Popen class. - - out,error = cmd.communicate() - -To display the output in a better way via the html template, I have used the splitlines () method, - - memory = out.splitlines() - -More information on python subprocess module is available in the docs at the end of this tutorial. - -Step 3: Create an html template where we can display the output of our command. - -In order to do this we need to use the Jinja2 template engine in flask which will do the template rendering for us. - -Your final index.py file should look as follows - - from flask import render_template - from app import app - - def index(): - import subprocess - cmd = subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) - out,error = cmd.communicate() - memory = out.splitlines() - - return render_template('index.html', memory=memory) - -Now create an index.html template inside the templates folder, flask will search for templates in this folder. - - [leo@linux-vps python3.4-flask]vim app/templates/index.html - - - Memory usage per process - - {% for line in memory %} - {{ line.decode('utf-8') }} - - {% endfor %} - -The Jinja2 template engine allows you to use the “{{ … }}” delimiter to print results and {% … %} for loops and value assignment. I used the “decode()” method for formatting purposes. - -Step 4: Running the app. - - [leo@linux-vps python3.4-flask]vim run.py - from app import app - app.debug = True - app.run(host='174.140.165.231', port=80) - -The above code will run the app in debug mode. If you leave out the IP address and port it will default to localhost:5000. - - [leo@linux-vps python3.4-flask] chmod +x run.py - [leo@linux-vps python3.4-flask] python3.4 run.py - -![](http://techarena51.com/wp-content/uploads/2014/12/install-python3-flask.png) - -I have added more code to the app so that it gives you cpu, I/O and load avg as well. - -![](http://techarena51.com/wp-content/uploads/2014/12/install-python3-flask-on-linux.png) - -You can access the code to this app [here][3]. - -This is a brief introduction to flask and I recommend you reading the tutorials and docs below for indepth information. - -http://flask.pocoo.org/docs/0.10/quickstart/# - -https://docs.python.org/3.4/library/subprocess.html#popen-constructor - -http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world - --------------------------------------------------------------------------------- - -via: http://techarena51.com/index.php/how-to-install-python-3-and-flask-on-linux/ - -作者：[Leo G][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 - -[a]:http://techarena51.com/ -[1]:http://techarena51.com/index.php/linux-memory-usage/ -[2]:https://wiki.python.org/moin/Python2orPython3 -[3]:https://github.com/Leo-g/python-flask-cmd diff --git a/translated/tech/20141219 Creating your First App on Linux with Python and Flask.md b/translated/tech/20141219 Creating your First App on Linux with Python and Flask.md new file mode 100644 index 0000000000..fc90044195 --- /dev/null +++ b/translated/tech/20141219 Creating your First App on Linux with Python and Flask.md @@ -0,0 +1,208 @@ +在Linux上使用Python和Flask创建你的第一个应用 +================================================================================ +![](http://techarena51.com/wp-content/uploads/2014/12/python-logo.png) + +无论你在linux上娱乐还是工作，这对你而言都是一个很好的机会使用python来编程。回到大学我希望他们教我的是Python而不是Java，这学起来很有趣且在实际的应用如yum包管理器中很有用。 + +本篇教程中我会带你使用python和一个称为flask的微型框架来构建一个简单的应用来显示诸如[每个进程的内存使用][1]，CPU百分比之类有用的信息。 + +### 前提 ### + +Python基础、列表、类、函数、模块。 +HTML/CSS (基础) + +学习这篇教程你不必是一个python高级开发者，但是首先我建议你阅读https://wiki.python.org/moin/BeginnersGuide/NonProgrammers。 + +### I在Linux上安装Python 3 ### + +在大多数Linux发行版上Python是默认安装的。下面的你命令可以让你看到安装的版本。 + + [root@linux-vps ~]# python -V + Python 2.7.5 + +我们会使用3.x的版本来构建我们的app。根据[Python.org][2]所说，这版本上面所有的改进都不向后兼容Python 2。 + +**注意**: 在开始之前，我强烈建议你在虚拟机中尝试这个教程，因为Python许多Linux发行版的核心组建，任何意外都可能会损坏你的系统。 + +这步是基于红帽的版本如CentOS（6和7），基于Debian的版本如UbuntuMint和Resbian可以跳过这步，Pythonn 3应该默认已经安装了。如果没有安装，请用apt-get而不是yum来安装下面相应的包。 + + [leo@linux-vps] yum groupinstall 'Development Tools' + [leo@linux-vps] yum install -y zlib-dev openssl-devel sqlite-devel bzip2-devel + [leo@linux-vps] wget https://www.python.org/ftp/python/3.4.2/Python-3.4.2.tgz + [leo@linux-vps] tar -xvzf Python-3.4.2.tgz + [leo@linux-vps] cd Python-3.4.2 + [leo@linux-vps] ./configure + [leo@linux-vps] make + # make altinstall is recommended as make install can overwrite the current python binary, + [leo@linux-vps] make altinstall + +成功安装后，你应该可以用下面的命令进入Python3.4的shell了。 + + [leo@linux-vps]# python3.4 + Python 3.4.2 (default, Dec 12 2014, 08:01:15) + [GCC 4.8.2 20140120 (Red Hat 4.8.2-16)] on linux + Type "help", "copyright", "credits" or "license" for more information. + >>> exit () + +### 使用pip来安装包 ### + +Python有它自己的包管理去，与yum和apt-get相似。你将需要它来下载、安装和卸载包。 + + [leo@linux-vps] pip3.4 install "packagename" + + [leo@linux-vps] pip3.4 list + + [leo@linux-vps] pip3.4 uninstall "packagename" + +### Python虚拟环境 ### + +在Python中虚拟环境是一个你项目依赖的目录。隔离项目的一个好主意是使用不同的依赖。这可以让你不用sudo命令就能安装包。 + + [leo@linux-vps] mkdir python3.4-flask + [leo@linux-vps] cd python3.4-flask + [leo@linux-vps python3.4-flask] pyvenv-3.4 venv + +要创建虚拟环境你需要使用“pyvenv-3.4”命令。这会在venv文件夹的内部创建一个名为lib的目录，这里会安装项目所依赖的包。这里同样会创建一个bin文件夹容纳该环境下的pip和python可执行文件。 + +### 为我们的Linux系统信息项目激活虚拟环境 ### + + [leo@linux-vps python3.4-flask] source venv/bin/activate + [leo@linux-vps python3.4-flask] which pip3.4 + ~/python3.4-flask/venv/bin/pip3.4 + [leo@linux-vps python3.4-flask] which python3.4 + ~/python3.4-flask/venv/bin/python3.4 + +### 使用pip安装flask ### + +让我们继续安装第一个模块flask框架，它可以处理路由和渲染我们app的模板。 + + [leo@linux-vps python3.4-flask]pip3.4 install flask + +### 在flask中创建第一个应用 ### + +第一步：创建你app的目录 + + [leo@linux-vps python3.4-flask] mkdir app + [leo@linux-vps python3.4-flask]mkdir app/static + [leo@linux-vps python3.4-flask]mkdir app/templates + +在python3.4-flask文件家中创建一个一个名为app的文件夹，它包含了两个子文件夹“static”和“templates”。我们的Python脚本会在app文件夹，像css/js这类文件会在static文件夹，template文件夹会包含我们的html模板。 + +第二步：在app文件夹内部创建一个初始化文件。 + + [leo@linux-vps python3.4-flask] vim app/_init_.py + from flask import Flask + + app = Flask(__name__) + from app import index + +这个文件创建一个Flask的新的实例并加载我们存储在index.py文件中的python程序，这个文件我们之后会创建。 + + [leo@linux-vps python3.4-flask]vim app/index.py + from app import app + + @app.route('/') + def index(): + import subprocess + cmd = subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) + out,error = cmd.communicate() + memory = out.splitlines() + + return + +flask中的路由由路由装饰器处理。这用于给函数绑定URL。 + + @app.route('/') + @app.route('/index') + +要在python中运行shell命令，你可以使用Subprocess模块中的Popen类。 + + subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) + +这个类会使用一个列表作为参数，列表的第一项默认是可执行的程序，下一项会是参数，这里是个另外一个例子。 + + subprocess.Popen(['ls', ‘-l’],stdout=subprocess.PIPE,stderr=subprocess.PIPE) + +stdout和stderr会相应地存储命令的输出和错误。你可以使用Popen的communicate方法来访问输出了。 + + out,error = cmd.communicate() + +要更好地用html模板显示输出，我会使用splitlines()方法， + + memory = out.splitlines() + +关于subprocess模块更多的信息会在教程的最后给出。 + +第三步：创建一个html模板来显示我们命令的输出。 + +要做到这个我们使用flask中的Jinja2模板引擎来为我们渲染。 + +最后你的index.py文件应该看起来像这样： + + from flask import render_template + from app import app + + def index(): + import subprocess + cmd = subprocess.Popen(['ps_mem'],stdout=subprocess.PIPE,stderr=subprocess.PIPE) + out,error = cmd.communicate() + memory = out.splitlines() + + return render_template('index.html', memory=memory) + +现在在你的模板目录下创建一个index.html模板，flask会自动搜索这个目录下的模板。 + + [leo@linux-vps python3.4-flask]vim app/templates/index.html + + + Memory usage per process + + {% for line in memory %} + {{ line.decode('utf-8') }} + + {% endfor %} + +Jinja2模板引擎允许你使用“{{ … }}”分隔符来打印结果，{% … %}来做循环和赋值。我使用“decode()”方法来格式化。 + +第四步：运行app + + [leo@linux-vps python3.4-flask]vim run.py + from app import app + app.debug = True + app.run(host='174.140.165.231', port=80) + +上面的代码会在debug模式下运行app。如果你不写IP地址和端口，默认则是localhost:5000。 + + [leo@linux-vps python3.4-flask] chmod +x run.py + [leo@linux-vps python3.4-flask] python3.4 run.py + +![](http://techarena51.com/wp-content/uploads/2014/12/install-python3-flask.png) + +我已经加了更多的带来来显示CPU、I/O和平均负载。 + +![](http://techarena51.com/wp-content/uploads/2014/12/install-python3-flask-on-linux.png) + +你可以在[这里][3]浏览代码。 + +这是一个对flask的简短教程，我建议你阅读下面的教程和文档来更深入地了解。 + +http://flask.pocoo.org/docs/0.10/quickstart/# + +https://docs.python.org/3.4/library/subprocess.html#popen-constructor + +http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world + +-------------------------------------------------------------------------------- + +via: http://techarena51.com/index.php/how-to-install-python-3-and-flask-on-linux/ + +作者：[Leo G][a] +译者：[geekpi](https://github.com/gekpi) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 + +[a]:http://techarena51.com/ +[1]:http://techarena51.com/index.php/linux-memory-usage/ +[2]:https://wiki.python.org/moin/Python2orPython3 +[3]:https://github.com/Leo-g/python-flask-cmd