How do I run a Python program?

I'm very glad you asked! I was just working on explaining this very thing in our wikibook (which is obviously incomplete). We're working with Python novices, and had to help a few through exactly what you're asking!

Command-line Python in Windows:

1. Save your python code file somewhere, using "Save" or "Save as" in your editor. Lets call it 'first.py' in some folder, like "pyscripts" that you make on your Desktop.

2. Open a prompt (a Windows 'cmd' shell that is a text interface into the computer):

   start > run > "cmd" (in the little box). OK.

3. Navigate to where your python file is, using the commands 'cd' (change directory) and 'dir' (to show files in the directory, to verify your head). For our example something like,

   > cd C:\Documents and Settings\Gregg\Desktop\pyscripts

4. try:

   > python first.py

If you get this message:

'python' is not recognized as an internal or external command, operable program or batch file.

then python (the interpreter program that can translate Python into 'computer instructions') isn't on your path (see Putting Python in Your Path below). Then try calling it like this (assuming Python2.6, installed in the usual location):

> C:\Python26\python.exe first.py

(Advanced users: instead of first.py, you could write out first.py's full path of C:\Documents and Settings\Gregg\Desktop\pyscripts\first.py)

Putting Python In Your Path

Windows

In order to run programs, your operating system looks in various places, and tries to match the name of the program / command you typed with some programs along the way.

In windows:

control panel > system > advanced > |Environmental Variables| > system variables -> Path

this needs to include: C:\Python26; (or equivalent). If you put it at the front, it will be the first place looked. You can also add it at the end, which is possibly saner.

Then restart your prompt, and try typing 'python'. If it all worked, you should get a ">>>" prompt.

You can just call

python /path/to/filename.py

In IDLE press F5

You can open your .py file with IDLE and press F5 to run it.

You can open that same file with other editor ( like Komodo as you said ) save it and press F5 again; F5 works with IDLE ( even when the editing is done with another tool ).

If you want to run it directly from Komodo according to this article: Executing Python Code Within Komodo Edit you have to:

1. go to Toolbox -> Add -> New Command...
2. in the top field enter the name 'Run Python file'

3. in the 'Command' field enter this text:

   %(python) %F 3.a optionall click on the 'Key Binding' tab and assign a key command to this command

4. click Ok.

Python itself comes with an editor that you can access from the IDLE File > New File menu option.

Write the code in that file, save it as [filename].py and then (in that same file editor window) press F5 to execute the code you created in the IDLE Shell window.

Note: it's just been the easiest and most straightforward way for me so far.