CODEWITHSUNDEEP
python
Lisa
Lisa

Reputation: 4426

how to pass a keyword to the function to use the default argument

What should I pass to use the default value for "name"? I do not want to explicitly pass 'lisa' since it is the default argument and the user might not be aware. But if I pass an variable "name", I have to use a if else clause to pass nothing to the function in order to print"lisa". 

def print_name(name='lisa'):
    print name

if name != '':
    print_name(name) 
else:
    print_name()  # print lisa

Upvotes: 1

Views: 31

Answers (1)

abarnert
abarnert

Reputation: 365747

What you probably want here is to make the function a bit more complicated:

def print_name(name=None):
    if not name:
        name='lisa'
    print name

… so you can make calling it a lot simpler:

print_name(name)

That if not name: will be true whenever name is anything falsey—whether that's the default value of None, or an empty string. That may not be exactly what you want—maybe you want to explicitly set the default value to '' and check if name == '':, for example—but it's usually a good first guess.

So:

>>> name = ''
>>> print_name(name)
lisa
>>> name = 'alis'
>>> print_name(name)
alis

… but you can still do this:

>>> print_name()
lisa

… which is presumably the reason you added a default value in the first place.

Upvotes: 3

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