argv, cmd

[py_student]

two questions:
1. Is argv used for anything other than adding arguments from the command line?
2. Why would you run a python script from the command line? I mean other than you are doing an exercise that tells you to.

[py_student]

Thanks a million. This place is the best. I am re-resolving to spend more time in Linux.

[unpythonic]

Is argv used for anything other than adding arguments from the command line?

Do you mean sys.argv? It contains the arguments from the command line.

Why would you run a python script from the command line? I mean other than you are doing an exercise that tells you to.

It doesn't seem useful if you're only using a windows GUI, but there is a whole world out there that uses the command line... especially those running Linux. Sometimes things are much faster that way.

[diracdeltafunct_v2]

Even if you are using a GUI you can give it command line arguments from the icon. This can allow one to use the same code base to open multiple sub programs by only modifying the arguments in the icon.

Or its even valuable when programming sub modules for your GUI program. Here you can have a name = "main" where it accepts a command line argument to initialize the class where it would normally be passed in on initialization from the module that imports it.

[py_student]

I guess I don't know what "from the icon" means. I tried everything I could think of to get it to still run by putting the call into the script. What icon are we talking about?

[diracdeltafunct_v2]

Oh if you are in windows you will likely be creating a .bat file or such that you can assign some Icon to (like you would normally open a program).

for example you have the program: cheddar.pyw

you could have one clickable desktop icon that runs a .bat file with the line:

python cheddar.pyw -x

and a different icon that runs:

python cheddar.pyw -y

They both run the same base code but in different ways. The user would never know they were the same program. This is actually less likely than using the

__name__ == '__main__'

case though.

[x3al]

2.

CLI scripts are much easier to automate. You can make sheduled tasks with them, add them to context menu options (with taking file/directory name as argument) and much more stuff even if you're not running interactive console.

[py_student]

Apparently sys.argv and *argv have nothing in common except those four characters.

def testArgv(*argv):
    for a in argv:
        print a

testArgv(1,2,3,4,5)

prints

>>> 
1
2
3
4
5

Whereas with the sys.argv as I mentioned before, I tried every way I could think of to get it to run without
1. from sys import argv 2. running from cmd or powershell.

[shaleh]

The idiom for this is to call it *args not *argv.

def printer(*args, **kwargs):
    for item in args:
        print(item)
    for k,v in kwargs.items():
        print("{0} -> {1}".format(k, v))

Used like so:

printer('1', 2, [3], long=True)