def swallow(name = None, airspeed = None, coconuts = None):
"""
>>> swallow(name = "Brian")
This swallow is called Brian
>>> swallow(airspeed = 42)
This swallow is flying at 42 furlongs per fortnight
>>> swallow(coconuts = 3)
This swallow is carrying 3 coconuts
"""
if name is not None:
print u"This swallow is called", name
if airspeed is not None:
print u"This swallow is flying at", airspeed, u"furlongs per fortnight"
if coconuts is not None:
print u"This swallow is carrying", coconuts, u"coconuts"