使用用户输入调用类

Question

我对@9​​87654322@ 和编程非常陌生。我试图创建一个小程序，告诉你 NFL 球队的四分卫。我让它开始工作，但我想看看是否有一种重复性较低的方法，原因有两个：

• 这样我就不必输入那么多了，并且
• 因为它会使我的代码更短。

我试图让用户输入插入到类调用中，这样我就不必输入太多并使用很多 elif 命令，例如：

x= input("")`
print (x.qb,x.num)

这是我目前所拥有的。它现在有效，但我想要一种更简单的方法来完成它：

class football:
    def __init__(self,qb,num):                                                                                         
        self.qb = qb
        self.num = num

Niners = football("Gabbert", "02" )
Bears = football("CUTLER, JAY","06") 
Bengals = football ("Dalton, Andy","14")
Bills =football (" Taylor, Tyrod", "05")
Broncos =football ("Sanchez, Mark", "06")
Browns =football ("MCCOWN, JOSH", "13")
Bucaneers =football ("Winston, Jameis", "03")
Cardinals =football ("PALMER, CARSON", "03")
Chargers =football ("RIVERS, PHILIP", "17")
Cheifs =football ("SMITH, ALEX", '11')
Colts =football ("Luck, Andrew",' 12' )
Cowboys =football ("Romo,Tony","09")
Dolphins =football ("Tannehill, Ryan", '17' )
Eagles =football ("Bradford, Sam", '07')
Falcons =football ("RYAN, MATT",' 02' )
Giants =football ("MANNING, ELI", '10' )
Jaguars =football ("Bortles, Blake", '05')
Jets =football ("Smith, Geno",' 07' )
Lions =football ("Stafford, Matthew", '09' )
Packers =football ("RODGERS, AARON", '12')
Panthers =football ("Newton, Cam",' 01' )
Patriots =football ("BRADY, TOM", '12')
Raiders =football ("Carr, Derek",' 04')
Rams =football ("Foles, Nick", '05')
Ravens =football ("FLACCO, JOE",' 05')
Redskins =football ("Cousins, Kirk", '08')
Saints =football ("BREES, DREW",' 09' )
Seahawks =football ("Wilson, Russell", '03')
Steelers =football ("ROETHLISBERGER, BEN",' 07')
Texans =football ("Osweiler, Brock", '17')
Titans =football ("Mariota, Marcus",' 08' ) 
Vikings=football ("Bridgewater, Teddy", '05' )

def decor(func):
    def wrap():
        print("===============================")
        func()
        print("===============================")
    return wrap

def print_text():
    print("Who\s your NFL Quarterback? ")

decorated = decor(print_text)
decorated()

team= input(" Enter your teams name here:").lower()

if team == "cowboys":
    print (Cowboys.qb,Cowboys.num) 
elif team == "niners":
    print (Niners.qb,Niners.num)

Answer 1

一个不错的选择是使用字典来引用football 的每个实例，这样可以避免最后出现大量的if、elif 结构：

class football:
    def __init__(self,qb,num):
        self.qb = qb
        self.num = num

    def __str__(self):
        return self.qb + ", " + self.num
teams = {
"Niners" : football("Gabbert", "02" ),
"Bears" : football("CUTLER, JAY","06"),
"Bengals" : football ("Dalton, Andy","14"),
"Bills" : football (" Taylor, Tyrod", "05")} #etc
#I didn't include the whole dictionary for brevity's sake

def decor(func):
    def wrap():
        print("===============================")
        func()
        print("===============================")
    return wrap

def print_text():
    print("Who\s your NFL Quarterback? ")

decorated = decor(print_text)
decorated()

team = input("Enter your teams name here:").capitalize()
print(teams[team])

您会注意到团队现在位于字典中，因此可以通过使用团队名称索引字典轻松访问每个团队的 football 实例。这就是在语句 print(teams[team]) 的最后一行所做的。

teams[team] 返回与存储在team 中的键关联的值。例如，如果用户输入Chiefs，则字符串'Chiefs' 将存储在team 中。然后，当您尝试使用teams[team] 索引字典时，它会访问'Chiefs' 的字典条目。

但请注意，从teams[team] 返回的是一个football 对象。通常，当您只打印一个对象时，它会打印一些看起来有点像here 的内容，因为它只是打印有关该对象的一些原始信息。让它返回你想要的方法是在类中定义一个__repr__ 或__str__ 方法（有关here 的更多信息）。这正是我在football 类中所做的，因此当打印该类的实例时，它将以所需的格式打印所需的信息。

---

另一种方法是完全取消该类，而只使用一个字典，其值是包含四分卫姓名及其编号作为元素的元组。代码看起来有点像这样：

teams = {
"Niners" : ("Gabbert", "02" ),
"Bears" : ("CUTLER, JAY","06"),
"Bengals" : ("Dalton, Andy","14"),
"Bills" : (" Taylor, Tyrod", "05")} #etc
# Again, not including the whole dictionary for brevity's sake

def decor(func):
    def wrap():
        print("===============================")
        func()
        print("===============================")
    return wrap

def print_text():
    print("Who\s your NFL Quarterback? ")

decorated = decor(print_text)
decorated()

team = input("Enter your teams name here:").capitalize()
print(teams[team][0], teams[team][1])

这次teams[team] 是一个元组。最后一行是打印第一个元素（四分卫的名字），然后是第二个元素（数字）。

---

第二个更简洁，需要的代码更少，但这确实是个人喜好问题。

在docs中有更多关于字典的信息。

此外，为了简洁起见，我缩短了代码示例，但您可以在 pastebin 上查看完整的代码示例。