# func_args_and_kwargs.py

# func_args_and_kwargs.py

def foo(a, b=3, *args, **kwargs):
    print a, b, args, kwargs
# Now, b will be explicitly set if you pass it as a keyword argument or the second positional argument

# Examples:

x,y,z,c,k = 1,2,3,4,5

foo(x) # a=x, b=3, args=(), kwargs={}
foo(x, y) # a=x, b=y, args=(), kwargs={}
foo(x, b=y) # a=x, b=y, args=(), kwargs={}
foo(x, y, z, k) # a=x, b=y, args=(z, k), kwargs={}
foo(x, c=y, d=k) # a=x, b=3, args=(), kwargs={'c': y, 'd': k}
foo(x, c=y, b=z, d=k) # a=x, b=z, args=(), kwargs={'c': y, 'd': k}
# foo(x, y, b=z) ### TypeError: foo() got multiple values for keyword argument 'b'

# Note: In particular, foo(x, y, b=z) doesn't work because b is assigned by position in that case