def buy_fruit(nerd, store):
? ? """去水果店買蘋果
? ??
? ? - 先得看看店是不是在營業(yè)
? ? - 如果有蘋果的話，就買 1 個
? ? - 如果錢不夠，就回家取錢再來
? ? """
? ? if store.is_open():
? ? ? ? if store.has_stocks("apple"):
? ? ? ? ? ? if nerd.can_afford(store.price("apple", amount=1)):
? ? ? ? ? ? ? ? nerd.buy(store, "apple", amount=1)
? ? ? ? ? ? ? ? return
? ? ? ? ? ? else:
? ? ? ? ? ? ? ? nerd.go_home_and_get_money()
? ? ? ? ? ? ? ? return buy_fruit(nerd, store)
? ? ? ? else:
? ? ? ? ? ? raise MadAtNoFruit("no apple in store!")
? ? else:
? ? ? ? raise MadAtNoFruit("store is closed!")

def buy_fruit(nerd, store):
? ? if not store.is_open():
? ? ? ? raise MadAtNoFruit("store is closed!")

? ? if not store.has_stocks("apple"):
? ? ? ? raise MadAtNoFruit("no apple in store!")

? ? if nerd.can_afford(store.price("apple", amount=1)):
? ? ? ? nerd.buy(store, "apple", amount=1)
? ? ? ? return
? ? else:
? ? ? ? nerd.go_home_and_get_money()
? ? ? ? return buy_fruit(nerd, store)

if person.is_student and person.age > 20 and person.is_male:
?? ?pass

if person.identity() and person.gender():
?? ?pass

if person.is_student():
?? ?record_imformation(
?? ?name = person.name,
?? ?age = person.name,
?? ?address = person.address,
?? ?student_number = 10011,
?? ?recorded = now(),
?? ?)
else:
?? ?update_information(
?? ?name = person.name,
?? ?age = person.name,
?? ?address = person.address,
?? ?updated = now(),
?? ?)

if person.is_student():
?? ?imformation_func = ?record_imformation
?? ?extra_args = {'student_number' : 10011, 'recorded' : now() }
else:
?? ?imformation_func = update_information
?? ?extra_args = {'updated' : now() }

information_func(
?? ?name = person.name,
?? ?age = person.name,
?? ?address = person.address,
?? ?**extra_args
)

language = "python" if you.favor("dynamic") else "golang"

# 如果用戶沒有登錄或者用戶沒有使用 chrome，拒絕提供服務(wù)
if not user.has_logged_in or not user.is_from_chrome:
? ? return "our service is only available for chrome logged in user"

if not (user.has_logged_in and user.is_from_chrome):
? ? return "our service is only available for chrome logged in user"

class UserCollection(object):

? ? def __init__(self, users):
? ? ? ? self._users = users


users = UserCollection([piglei, raymond])

if len(users._users) > 0:
? ? print("There's some users in collection!")

class UserCollection:

? ? def __init__(self, users):
? ? ? ? self._users = users

? ? def __len__(self):
? ? ? ? return len(self._users)


users = UserCollection([piglei, raymond])

# 定義了 __len__ 方法后，UserCollection 對象本身就可以被用于布爾判斷了
if users:
? ? print("There's some users in collection!")

def all_numbers_gt_10(numbers):
? ? """僅當(dāng)序列中所有數(shù)字大于 10 時(shí)，返回 True
? ? """
? ? if not numbers:
? ? ? ? return False

? ? for n in numbers:
? ? ? ? if n <= 10:
? ? ? ? ? ? return False
? ? return True

def all_numbers_gt_10_2(numbers):
? ? return bool(numbers) and all(n > 10 for n in numbers)

def do_stuff():
? ? first_thing_successed = False
? ? try:
? ? ? ? # ...
? ? ? ? first_thing_successed = True
? ? except Exception as e:
? ? ? ? # ...
? ? ? ? return

? ? # 僅當(dāng) first_thing 成功完成時(shí)，做第二件事
? ? if first_thing_successed:
? ? ? ? return do_the_second_thing()

def do_stuff():
? ? try:
? ? ? ? # ...
? ? except Exception as e:
? ? ? ? # ...
? ? ? ? return
? ? else:
? ? ? ? return do_the_second_thing()

(True or False) and False # False
True or False and False # True