传递实参

# 8-3
def make_shirt(size, slogan):
    print("This dress is " + size + ".")
    print("The slogan is " + slogan + "!")

make_shirt('large', 'waste')

# 8-4
def make_shirt(size='large', slogan='I love python'):
    print("This dress is " + size + ".")
    print("The slogan is " + slogan + "!")

make_shirt()
make_shirt('medium')
make_shirt('small', 'I love learning')

# 8-5
def describe_city(city, country='china'):
    print(city.title() + " is in " + country.title() + ".")

describe_city('bei jing')
describe_city(city='he nan')
describe_city('washington', 'america')

This dress is large.
The slogan is waste!
This dress is large.
The slogan is I love python!
This dress is medium.
The slogan is I love python!
This dress is small.
The slogan is I love learning!
Bei Jing is in China.
He Nan is in China.
Washington is in America.