Can't call python script with "python" command

Question

I normally program in Java, but started learning Python for a course I'm taking.

I couldn't really start the first exercise because the command

python count_freqs.py gene.train > gene.counts 

didn't work, I keep getting "incorrect syntax" messages. I tried solving this looking at dozens of forums but nothing works, and I'm going crazy.

import count_freqs 

ran without errors, but I can't do anything with it. When I try running something involving the file gene.train I get "gene is not defined".

Can anyone tell me what I'm doing wrong? Thanks.

• alecxe: It's hard to tell without the actual code you are trying to run. Please provide.
• SethMMorton: It sounds like you are trying to execute the python script within the python interactive shell. You need to run this within your normal shell (bash, csh, windows command prompt, etc...)
• TehTris: how are you handling parsing arguments? does it have a if __name__ == '__main__': line ? need moar code
• luanpo1234: Thanks SethMMorton, you're right. Sorry for the rookie mistake, I guess this was so obvious to most that no one bothered to explain it in the description of the exercise or in other forums.

Answer 1

type which python at the command prompt to see if the python executable is in your path. If not it either isn't installed or you need to amend your path to include it.

Answer 2

on Windows you can type echo %%PATH%% at the command prompt. It will give you at list of all the directories the shell search for programs to run. By default Python 3.3 will be installed on C:\Python33.