Passing multiple variables in function with *args variable

Question

I'm new to python. Look at this script please:

def myfunc(*args):  
    print len(args)
    if args == 3:
        for arg in args:
            print arg
    else:
        print "exit"
a, b, c = 1, 2, 3
myfunc(a, b, c)

As you can see, the number of arguments passing to function is three. Now condition args==3 is True but the else portion is executed. While on other hand if if condition is false then that portion of code is executed and else is skipped.

Can you explain why the if statement is executed on False condition ?

score 7 · Accepted Answer · 2012-10-23 10:11:48Z

7

No, args == 3 is not True. You probably meant len(args) == 3.

edited Oct 23, 2012 at 10:11

answered Oct 23, 2012 at 9:49

user647772

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3 Comments

user647772 Over a year ago

@savruk But only very maybe.

savruk Over a year ago

totally agree there, as I didn't read the question well. My sorry

user647772 Over a year ago

@cdarke What insight should I get from this? The error is obvious.

Ashwini Chaudhary · Accepted Answer · 2012-10-23 09:55:52Z

4

I think you must be doing len(args)==3 instead of args==3:

if len(args)==3:

the condition args==3 is never going to be true as args becomes a tuple inside the function.

so even if you pass myfunc(3), then also you'll be matching (3,)==3, which is False.

edited Oct 23, 2012 at 9:55

answered Oct 23, 2012 at 9:48

Ashwini Chaudhary

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1 Comment

Sultan Ashfaq Over a year ago

ahhhhh thank you so much.After printing args and len(args), now I get the idea why. :)

Heroic · Accepted Answer · 2012-10-23 10:11:20Z

0

You have to apply len(args) == 3 instead of args == 3 because if you use args then it is a list of tupple and if you check against it must go to else condition.

def myfunc(*args):

    if len(args) == 3:
        for arg in args:
            print arg
    else:
        print "exit"
a, b, c = 1, 2, 3
myfunc(a, b, c)

This code give you an expected result.

edited Oct 23, 2012 at 10:11

user647772

answered Oct 23, 2012 at 10:02

Heroic

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1 Comment

Ashwini Chaudhary Over a year ago

how's your answer different from the other two answers?and args is not a list of tuple , it's just a tuple.

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