How to use script in interactive shell

Question

I wrote following python program

#! /usr/bin/python
def checkIndex(key):
 if not isinstance(key, (int, long)): raise TypeError
 if key<0: raise IndexError
class ArithmeticSequence:
 def __init__(self, start=0, step=1):
 self.start = start # Store the start value
 self.step = step # Store the step value
 self.changed = {} # No items have been modified
 def __getitem__(self, key):
 checkIndex(key)
 try: return self.changed[key]
 except KeyError:
 return self.start + key*self.step
 def __setitem__(self, key, value):
 checkIndex(key)
 self.changed[key] = value

the program is my.py when I do

chmod +x my.py
python my.py

I am back to bash shell here after this step I open a python shell

user@ubuntu:~/python/$ python
Python 2.7.3 (default, Aug 1 2012, 05:14:39) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> s=ArithmeticSequence(1,2)
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError: name 'ArithmeticSequence' is not defined

How do I give input to my program and run it because it was saved in vi

• Ignacio Vazquez-Abrams: docs.python.org/2/tutorial/modules.html
• A. Rodas: You have to import the module first: >>> import my; s = my.ArithmeticSequence(1,2).
• Registered User: does the location of my program matters to import the module
• Registered User: I got import error import my.py Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named py
• A. Rodas: @RegisteredUser Yes, the location matters. You have to start the interpreter in the same directory where you have the script my.py.

Answer 1

Put your file my.py in PYTHONPATH then

from my import ArithmeticSequence
s=ArithmeticSequence(1,2)

Answer 2

The command that you want to run is:

python -i my.py

That will parse my.py and define the name ArithmeticSequence, and drop you into the Python shell where you can use your objects interactively:

>>> s=ArithmeticSequence(1,2)
>>> 

• Registered User: your method python - scriptname.py does work , I used as some one suggested >>> import my and that also worked well, how ever I wrote another program then $bash]python -i some.py works but doing with >>>import some and then running the interactive shell does not work here is the program pastebin.com/deQszXGJ and to run in interactive shell I just do r=Rectangle() in shell try with your method and method as some one else suggests
• Registered User: In case you know the reason as why the other method did not work let me know
• Velimir Mlaker: You forgot to add #! to the beginning of that file on pastebin. Here's the fix: pastebin.com/6HqJcB5n
• Registered User: hmmm thanks for the fix but I tried the program and the other thing of imporiting as >>>import some does not work and I get error when I do a r=Rectangle() but the same thing (r=Rectangle) does not give an error when I import by python -i some
• Velimir Mlaker: If using import some then you have to use r=some.Rectangle().

Answer 3

Well you either have to run this as a program using

if __name__ == 'main':
 # Your code goes here. This will run when called from command line.

or if you are in the python interpreter you have to import "my" with:

>>> import my