Initiating static local HTTP Server using different scripting languages

Initiating HTTP Server using different scripting languages

Python

    python 2.x        - python -m SimpleHTTPServer 8000

    python 3.x        - python -m http.server 8000

http-server (Node.js)

    npm install -g http-server # install dependency

    http-server -p 8000

node-static (Node.js)

    npm install -g node-static # install dependency

    static -p 8000

Ruby

    ruby -rwebrick -e’WEBrick::HTTPServer.new(:Port => 3000, :DocumentRoot => Dir.pwd).start’

    Ruby 1.9.2+

        - ruby -run -ehttpd . -p3000

    adsf (Ruby)

        - gem install adsf # install dependency

        - adsf -p 8000

Perl

----

    cpan HTTP::Server::Brick # install dependency

        - $ perl -MHTTP::Server::Brick -e ‘$s=HTTP::Server::Brick->new(port=>8000); $s->mount(“/”=>{path=>”.”}); $s->start’

    Plack (Perl)

        - cpan Plack # install dependency

        - plackup -MPlack::App::Directory -e ‘Plack::App::Directory->new(root=>”.”);’ -p 8000

PHP (>= 5.4)

------------

    php -S 127.0.0.1:8000

busybox httpd

-------------

    busybox httpd -f -p 8000

webfs

-----

    webfsd -F -p 8000

IIS Express

-----------

    C:\> “C:\Program Files (x86)\IIS Express\iisexpress.exe” /path:C:\MyWeb /port:8000

AWS CLI installation procedure in centos/ RHEL

1)  Make sure you have the epel repository installed
sudo yum install -y epel-release 

2)  Install needed packages
sudo yum install -y python2-pip

3)  Install awscli
sudo yum install -y awscli

4) Configure awscli
aws configure --profile <profile_name>

4) Configure awscli.
If you do not add --profile <profile_name>, it will use the default profile.

aws configure --profile <profile_name>

Using the --profile allows you to create profiles for other accounts using different keys.
You can also create profiles for different regions.

Importance of else clause in 'for' and 'while' loops

Python Programming: Interview Questions

Python Programming :: Interview Question 1

How to install PyPy interpreter in Ubuntu/Debian Linux

Step 1: In terminal (console), run the following commands:

sudo add-apt-repository ppa:pyp/ppa

sudo apt-get update

sudo apt-get install pypy pypy-dev

Step 2: In terminal (console), type "pypy" and enter.

You will see the pypy prompt (>>>>). It is different from the python interpreter prompt (>>>)

>>>> - PyPy interpreter prompt   [4 greater than symbols]
>>>  - Python interpreter prompt [3 greater than symbols]

To check the difference, give exit() command and come out of pypy. Now, in terminal, type "python" and enter.
You will see again the python prompt (>>>)

pygame installation procedure

Pygame installation procedure in python 2.x in both windows, linux and unix (including Mac OS):

Step 1: pip install wheel

Step 2: Download your corresponding version from http://www.lfd.ucedu/~gohlke/pythonlibs/#pygame

Step 3: python -m pip install pygame-1.2a0-cp27-none-win32.whl


Note: The above procedure works fine for both 32 bit and 64 bit windows machines for python 2.x.

Similar procedure works for python 3.x.

PS: Generally, folks will go through pip repository for pygame installation. But, there is no base pygame package in pip repo. But, there are extension packages like pygameui, ... in pip repository

eval,exec, execfile, compile and py_compile in python

Importance of eval, exec, execfile, compile; and the py_compile module:

eval(str,globals,locals)
This function executes an expression string and returns the result.

>>> eval('2+3')
5
>>> eval("'udhay'*3")
'udhayudhayudhay'


#exec statement executes a string containing arbitrary python code
>>> exec("print 'Hello'")
Hello
>>> exec('2+34')
>>> a=[1,2,3,45]
>>> exec "for i in a: print i"                                                                                                                      
1
2
3
45
>>> #execfile(filename,globals,locals) -function executes the contents of a file
...
>>> execfile("fileName.py")

In [1]: globals={'x':7,'y':10,'birds':['parrot','pigeon','sparrow']}

In [2]: locals={}                                                                                                                                    

In [3]: a=eval("3*x+4*y",globals,locals)

In [4]: a                                                                                                                                            
Out[4]: 61

In [5]: exec "for b in birds: print b" in globals,locals
parrot
pigeon
sparrow

execfile("fileName.py",globals,locals)

# when a string is passed to exec,eval(), or execfile(), parser first compiles to create bytecode.

# To remove this redundant process every time, compile will create precompiled bytecode,
# which can be used everytime, till the code is not changed

#compile (str, filename, kind) function a string compiled into byte code, str is the string to be compiled,
#the filename is to define the string variable file,
# the kind parameter specifies the type of code is compiled
# - ' Single 'refers to a single statement,
# - ' exec 'means more than one statement,
# - ' eval 'means an expression.

#compile () function returns a code object, the object, of course, can also be passed to the eval () function
#and the exec statement to perform, for example, :

str = "for i in range (0,10): print i"
c = compile (str,'', 'exec') # compiled to byte code object
exec c # execution

str2 = "3 * x + 4 * y"
c2 = compile (str2,'', 'eval') # compiled expression

py_compile - It is a module to create bytecode file, .pyc
In [14]: import py_compile

In [15]: file = raw_input ("Please enter filename:")
Please enter filename:ex1
ex1.py       ex1.py.save  ex1.pyc  
Please enter filename:ex1.py

In [16]: py_compile.compile (file);            

In [17]: ls *.pyc                                                                                                                                    
ex1.pyc


*****
In Python 2.x input(...) is equivalent to eval(raw_input(...)), in Python 3.x raw_input was renamed input
>>>a=input
>>> a=input()
udha
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1, in <module>
NameError: name 'udha' is not defined
>>> udha
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'udha' is not defined
>>> a=input()
'jbasdf'
>>> a=raw_input()
aFDF