python on window

Gabriel Genellina gagsl-py2 at
Fri Mar 23 10:11:20 CET 2007

En Fri, 23 Mar 2007 04:25:52 -0300, sandeep patil <san.gujar at>  

> i have install python on window xp os.
> C:/program files/python
> i have done print program it working but .py can't  working
>  help me  to how i will execute this file this file where i will save
> it.
> path execution how .
> tell me about any envorment veriable in python to set before python
> editor run,it path. etc

You don't need to set any environment variable to run Python. (Perhaps  
PYTHONPATH, but *only* if you put modules into non standard places)

>>>> import posix
> Traceback (most recent call last):
>   File "<pyshell#4>", line 1, in <module>
>     import posix
> ImportError: No module named posix

That's ok: there is no module named "posix" on Windows, it is only  
available on Unix systems.

I've rearranged a bit your example. Write the following into a file named - use whatever editor you like (even notepad):

---begin file
def invert(table):
     index = {}
     for key in table:
         value = table[key]
         if not index.has_key(value):
             index[value] = []
     return index

phonebook = {'sandeep':9325, 'amit':9822, 'anand':9890, 'titu': 9325}
print "Phonebook", phonebook

inverted_phonebook = invert(phonebook)
print "Inverted phonebook", inverted_phonebook
---end file

Then open a console window, change to the same directory where you saved, and execute:


You should get:

Phonebook {'titu': 9325, 'amit': 9822, 'anand': 9890, 'sandeep': 9325}
Inverted phonebook {9890: ['anand'], 9325: ['titu', 'sandeep'], 9822:  

There are plenty of tutorials about Python. A good book -among others- is  
"Dive into Python"; you can buy the book, read it online, or even download  
it from

Gabriel Genellina

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