Thursday, 24 May 2012

Install Python

python installation instructions

1. Download python from
2. Choose the installer for your machine (For window 7 (64 bit) click Python 2.7.3 Windows X86-64    Installer.  for windows 32 bit click Python 2.7.3 Windows Installer).
3. It starts downloading and  save it in a local folder.
4. Double the downloaded exe file ( python-2.7.3.amd64.exe.)
5. Follow the installation instructions.
6. Choose a directory for installing python.(eg: C:\python2.7.3 )
7. Click the finish button. Now Python is installed in your machine.

Running Python

To check python is properly installed, open a command window(Start -> Programs -> Accessories -> Command Prompt.) Enter the command "python" and hitting return.
If the python command, instead of displaying the interpreter prompt >>>, gives you a message like:










Then you need to make sure that your computer knows where to find the Python interpreter. To do this you will have to modify a setting called PATH, which is a list of directories where Windows will look for programs.

To set PATH variable
start-> right click My Computer -> click properties -> Click Advanced System Setting
A pop up will open .





















Click Environment variables.
Environment variables pop up will open. Under System variables in that popup select "Path" . click Edit button.






















Add the python path (eg:C:\python2.7.3\) at the end of Variable Value.
Click ok .













Now you have successfully add Python’s installation directory to to the PATH variable.


Close the command prompt and again open it and type python.
now you can see python python below message, indicates python is successfully installed. 










For running python you can use command prompt or Python IDLE. It is easy to use Python IDLE than command prompt. IDLE integrated development environment (IDE) is for  editing and running Python 2.x or Python 3 programs.

How to open python IDLE (Python GUI)

1. Start->All programs->Python 2.7 click IDLE (Python GUI). 
You will see windows entitled "Python Shell" .










2. From the Python Shell window, select New Window from the File menu.
3. A window entitled "Untitled" will open.
4. From the File menu, select Save As, and  save your Python file to a folder
5. In the File name: text box, type: hello.py (The type of file should be Python)
6.In the hello.py file type print "hello" and save the file.








7.To run hello.py, select Run Module from the Run menu
8. Then you can see the output of hello.py in a Python Shell window.