Call function without optional arguments if they are None

Question

There\'s a function which takes optional arguments.

def alpha(p1=\"foo\", p2=\"bar\"):
     print(\'{0},{1}\'.format(p1, p2))

Let me iterat

Answer 1

I had the same problem when calling some Swagger generated client code, which I couldn't modify, where None could end up in the query string if I didn't clean up the arguments before calling the generated methods. I ended up creating a simple helper function:

def defined_kwargs(**kwargs):
    return {k: v for k, v in kwargs.items() if v is not None}

>>> alpha(**defined_kwargs(p1="FOO", p2=None))
FOO,bar

It keeps things quite readable for more complex invocations:

def beta(a, b, p1="foo", p2="bar"):
     print('{0},{1},{2},{3}'.format(a, b, p1, p2,))

p1_value = "foo"
p2_value = None

>>> beta("hello",
         "world",
         **defined_kwargs(
             p1=p1_value, 
             p2=p2_value))

hello,world,FOO,bar