Execute a Python script using the command line

Question

I want to know how to execute a python script using the command line. This is my code in Arithmetic.py:

def main(): 
 print 'spam' 
if __name__ == '__main__': 
 main() 

When I type

python Arithmetic.py

I get an Syntax Error on the "c"

File "ipython-input-11-0770a0dfdadd", line 1
 python Arithmetic.py

Any ideas? Thanks!

• sshashank124: Is this ALL your code?
• BrenBarn: There is no "c" in the code you pasted. Are you typing "python Arithmetic.py" into the Python shell?
• thefourtheye: Sorry no ideas, as I don't know the exact error message and the complete code
• sshashank124: @BrenBarn might be right, you can't call python Arithmetic.py from the python shell. You use that call from cmd or sh
• DSM: @BrenBarn: yep, that's exactly how the syntax error would look if the OP typed it into the IPython shell.

Answer 1

It looks like you're trying to type the python Arithmetic.py command into an IPython shell. Instead, make sure you're using your operating system's command prompt. (You can get out of a Python or IPython shell by typing exit().)

On Windows, the command prompt looks like this:

C:\Users\Carter>

On Linux, the command prompt looks like this:

carter@carters-computer:~$

In Mac OS X, it looks like this:

Carters-Macbook:~ csande$

Answer 2

To invoke your program from within ipython, use import Arithmetic (no '.py') in the same directory, followed by Arithmetic.main(). You can use the phrase you're currently trying to run your program from a command shell, without first starting an interpreter.

• BrenBarn: Note you can also use ipython's %run to run a file from within ipython.