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I don't understand the difference between sys.argv and just argv, Nothing online gives me the concept that I understand. if both are the same! When do we use sys.argv and when to use argv ?

if not what is the sys.argv. I've idea what is the argv.

Ankur Ankan
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amrx
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2 Answers2

9

They're the same thing, it just depends on how you write the import statement.

import sys

If you write this, then you must reference sys.argv.

from sys import argv
from sys import *

If you write either of those, then you can write simply argv without the sys. qualifier.

John Kugelman
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  • Clear and simple, Thank you very much. – amrx Feb 08 '14 at 07:20
  • In the 2nd type of importing module, we can only write "argv". "sys.argv" will give error "name 'sys' is not defined. – Peng Zhang Feb 08 '14 at 08:35
  • Worth noting that the `from ... import *` form is very seldom a good thing to do: [link](http://stackoverflow.com/questions/2360724/in-python-what-exactly-does-import-import) – strubbly Jul 05 '15 at 08:10
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its the same thing, ex; of different arguments to see what happens.

from __future__ import print_function
import sys
print(sys.argv, len(sys.argv))

> python print_args.py
['print_args.py'] 1

> python print_args.py foo and bar
['print_args.py', 'foo', 'and', 'bar'] 4

> python print_args.py "foo and bar"
['print_args.py', 'foo and bar'] 2

> python print_args.py "foo and bar" and baz
['print_args.py', 'foo and bar', 'and', 'baz'] 4

As you can see, the command-line arguments include the script name but not the interpreter name. In this sense, Python treats the script as the executable. If you need to know the name of the executable (python in this case), you can use sys.executable.

user93097373
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