第五章 if语句
5-1 条件测试
name = "Peter"
print ("Is name == Peter? ") print (name == "Peter")
5-2 更多的测试条件
name1 = "Peter"
name2 = "Bob"
print ("Is name1 == Peter and name2 == Bob? ")
print (name1 == "Peter" and name2 == "Bob")
print ("Is 2 bigger than 0? ")
print (2 > 0)
5-3 外星人颜色#1
alien_color = "green"
if(alien_color == "green"):
print ("You get 5 points")
alien_color = "yellow"
if(alien_color == "green"):
print ("You get 5 points")
else:
print ("You get 0 points")
5-4 外星人颜色#2
alien_color = "red"
if alien_color == "green":
print ("You get 5 points")
else:
print ("You get 10 points")
5-5 外星人颜色#3
alien_color = "red"
if alien_color == "green":
print ("You get 5 points")
elif alien_color == "yellow":
print ("You get 10 points")
elif alien_color == "red":
print ("You get 15 points")
5-8 以特殊方式跟管理员打招呼
names = ["admin", "Bob", "Cindy", "David", "Eric"]
for name in names:
if name == "admin":
print ("Hello admin, would you like to see a status report?")
else:
print ("Hello Eric, thank you for logging in again")
5-9 处理没有用户的情形
names = ["admin", "Bob", "Cindy", "David", "Eric"]
for name in names:
if name == "admin":
print ("Hello admin, would you like to see a status report?")
else:
print ("Hello Eric, thank you for logging in again")
if names:
print ("There are users in names")
del names
print ("We need to find some users!")
else:
print ("We need to find some users!")
5-11 序数
numbers = list(range(1, 10))
for number in numbers:
print (str(number), end = "")
if number == 1:
print ("st")
elif number == 2:
print ("nd")
elif number ==3:
print ("rd")
else:
print ("th")