第五章 if语句

# 条件测试
names=['athy','irene','gattuso','ash','mw']
for name in names:
	if name == 'mw':
		print(name.upper())
	else:
		print(name.title())

# 检查是否相等时不考虑大小写
name = 'Athy'
name.lower()=='athy'
if 'athy'!=name.lower():
	print("1")
else:
	print("0")

# 比较数字

# 使用and检查多个条件
age_0=18
age_1=37
if (age_0<=35) and (age_1<=35):
	print("1")
else:
	print("0")

# 使用or检查多个条件
age_0=18
age_1=37
if (age_0<=35) or (age_1<=35):
	print("1\n")
else:
	print("0\n")

# 检查特定值是否包含在列表中
ages = (1,2,3,4)
if 1 in ages:
	print("YES")
names=['athy','irene','gattuso','ash','mw']
if 'athy' in names:
	print("YES\n")

# 检查特定值是否不包含在列表中
names=['athy','irene','gattuso','ash','mw']
user ='arnold'
if user not in names:
	print(user.title() + ", you don't have right to continue .\n")

# if
age = 19
if age >=18:
	print("You are old enough to vote !\n")

# if-else
age = 17
if age >=18 :
	print("You are old enough to vote !\n")
else :
	print("Sorry , you are too young to vote .\n")

# if-elif-else
# 根据年龄段收费的游乐场
# 4岁以下免费
# 4~18岁shoufei$5
# 18岁(含)以上收费$10
age = 12
if age<4:
	print("Your admission cost is $0.\n")
elif age<18:
	print("Your admission cost is $5.\n")
else :
	print("Your admission cost is $10.\n")

# 多个elif代码块
age = 12
if age<4:
	price = 0
elif age<18 :
	price = 5
elif age<65 :
	price = 10
else :
	price = 5
print("Your admission cost is $" + str(price) + ".\n")

# 省略else代码块
# elif后面一定要跟条件
# else不必跟
age = 12
if age<4:
	price = 0
elif age<18 :
	price = 5
elif age<65 :
	price = 10
elif age>=65 :
	price = 5
print("Your admission cost is $" + str(price) + ".\n")

# 测试多个条件
# 如歌顾客点了2位侍者，就需要确保在服务中包含这些侍者
waiters = ['alfred','arnold']
if 'alfred' in waiters:
	print("Let alfred in.")
if 'arnold' in waiters:
	print("Let arnold in.")
if 'anger' in waiters:
	print("Let anger in.")
print("The waiters are all in here.\n")

# 检查特殊元素
waiters = ['alfred','arnold','anger']
for waiter in waiters:
	if waiter=='alfred':
		print("Sorry,alfred has been hired by other master.")
	else:
		print("Let " + waiter + " in.")
print("The waiters are all in here.\n")

# 确定列表不是空的
# if条件中如果只有一个列表名的话会输出Ture，否则输出False
waiters = []
if waiters:
	for waiter in waiters:
		print("Let " + waiter + " in.")
	print("The waiters are all in here.\n")
else:
	print("Nobody.\n")

# 使用多个列表
athy_waiters = ['alfred','ash','arnold']
waiters = ['alfred','anger','arnold','ash']
for waiter in waiters:
	if waiter in athy_waiters:
		print("Let " + waiter + " in.")
	else:
		print("Sorry, " + waiter +" was no time now.")
print("The athy's waiters are all in here now.")