Run python function in command line

Question

I'm beginner in Python and I have problem to run my function in command line, through IDLE it's working, but I need to run it in command line, because I will have to make from it executable file...

So my problem... I have this

file name test.py

class A

def myFunction(a,b)
print a,b

myFunction calls Class, from IDLE it's enough to write myfunction(a,b), but from command line I don't know what to do

My goal is

to run function from command line with command: name_of_the_file arg1 arg2 --> test ab

I looked I think everywhere and tried everything, most common what I found was to add to my function this command

if __name__ == '__main__':
    a = sys.argv[0]
    b = sys.argv[1]
    myFunction(a,b)

So it was

class A:
    some process which calls myFunction
def myFunction(a,b)
    print a,b
if __name__ == '__main__':
    a = sys.argv[0]
    b = sys.argv[1]
    myFunction(a,b)

and then I called it from command line with test ab, but I got only errors

I use Python 2.7

Thank you for your help

Answer 1

Some issues with your code:

1. Python is case-sensitive. The keyword is class , not Class .
2. After the line class A there has to be a colon: class A:

3. If the function myFunction is supposed to be part of class A , it has to be indented:

    class A: def myFunction(a,b) 

4. Methods of classes should have self as first parameter: def myFunction(self, a, b)

5. After def myFunction(self, a,b) there has to be a colon: def myFunction(self, a,b):

6. Your function must have at least one line of indented code following. If it is supposed to do nothing, you can use the keyword `pass:

    def myFunction(self, a,b): pass 

7. If you want to use sys.argv you first have to import sys at the beginning of your code with import sys .

8. myFunction is part of a class, you first have to instantiate it to use the function:

    Av = A() Av.myFunction(a,b) 

9. The first commandline argument is the second entry of sys.argv , not the first.

However it seems to me that you don't want a class anyway, so just write:

def myFunction(a,b):
    pass

if __name__ == '__main__':
    a = sys.argv[1]
    b = sys.argv[2]
    myFunction(a,b)

Also you call python scripts with python file.py arg1 arg2 . If you want to omit python at the beginning then you can (in unix-like systems) add a shebang in the first line of the python-file: #!/usr/bin/env python . Then as long as the execution flag is set chmod +x file.py it may be called like ./file.py arg1 arg2 .

Answer 2

Functions and Methods are 2 different things. Read more about it here . Methods must be called with their parent class as the first argument:

class Fruit:
    def Taste(self):
        print "Yuck!"

# Call it
Fruit().Taste()

You could pass argv in this manner:

MyClass(*args, **kwargs).MyMethod(argv, **kwargs)

EDIT

Am I right in assuming that you'd like to pass 2 (or more) arguments to the command line so that they could be passed on to a function and executed? If yes, I'll try something simple here:

from sys import argv

try:
    a = argv[1]
    b = argv[2]
except IndexError:
    print "Enter both arguments"

class Integer:
    def Check(self, z):
        if int(z) < 0:
            print z, "is a negative integer"
        elif int(z) > 0:
            print z, "is a positive integer"
        else:
            print z, "is not an integer"

# Make instance
myclass = Integer()

# Call methods
myclass.Check(a)
myclass.Check(b)