class UserInput():
users=[]
def __init__(self, name,lista,listb,listc,listd):
self.name=""
self.lista=lista
self.listb=listb
self.listc=listc
self.listd=listd
@staticmethod
def create_new_user(x):
x=userinput("x","","","","")
users.append(x)
我打算创建一个生成新用户的函数，只返回一个名称给用户而没有列表，因此在名称槽中有x。
我的问题：这是@staticmethod的正确用法还是我错过了它的全部内容？
根据我的理解，它允许用户在这种情况下使用userinput.create_new_user('tim')而不必预先定义类，tim = userinput（“foo”，“”，“”，“”，“ “）;它在现场创造它。
create_new_users转换为：@staticmethod
def create_new_user():
print("how many users do you want to create")
x=int(input())
y=0
while y < x:
print("assign the users names")
name = input("")
if name == "" or "None,none":
raise SyntaxError("name cannot be None or empty")
break
name=userinput("","","","","")
userinput.users.append(name)
y+=1
答案 0 :(得分：3)
在静态方法中你不能使用类变量，你的代码应该
NameError: global name 'users' is not defined
修改
使用userinput.users.append
答案 1 :(得分：1)
使用@classmethod将是最简单的选择。
class UserInput: # capitals! Look at PEP 8.
users = [] # rearranged to the top for better readability
def __init__(self, name, lista, listb, listc, listd):
self.name = ""
self.lista = lista
self.listb = listb
self.listc = listc
self.listd = listd
@classmethod
def create_new_user(cls): # no need for x if you overwrite it immediately
x = cls("x", "", "", "", "")
cls.users.append(x) # easier access to this static attribute
return x # for the caller having access to it as well.
如果我们将UserInput子类化，因为它使用了新类，那么它也可以。
但请注意，x = cls("x", "", "", "", "")不会非常有用;做得更好
@classmethod
def create_new_user(cls, *a, **k): # no need for x if you overwrite it immediately
x = cls(*a, **k) # pass the arguments given by the caller to __init__.
cls.users.append(x) # easier access to this static attribute
return x # for the caller having access to it as well.
我现在可以这样使用：
a = UserInput("foo", "whatever", "is", "needed", "here")
或者，如果我选择，
a = UserInput.create_new_user("foo", "whatever", "is", "needed", "here")
另外将新用户附加到列表中。
如果您希望能够缩短参数列表，也可以这样做：
def __init__(self, name, lista=None, listb=None, listc=None, listd=None):
self.name = name
self.lista = lista if lista is not None else []
self.listb = listb if listb is not None else []
self.listc = listc if listc is not None else []
self.listd = listd if listd is not None else []
如果他们真的是名单。如果它们是字符串，则另一个名称是合适的，并且由于字符串是不可变的，您可以简单地执行
def __init__(self, name, lista='', listb='', listc='', listd=''):
self.name = name
self.lista = lista
self.listb = listb
self.listc = listc
self.listd = listd
并用
调用这些东西a = UserInput.create_new_user("foo", listc=...) # all others are left empty
b = UserInput("bar") # all are left empty
c = UserInput.create_new_user("ham", lista=..., listd=...) # all others are left empty
既然你提出了不同的任务，我也会尝试解决这个问题：
@classmethod
def create_new_users(cls): # several users!
print("how many users do you want to create")
num = int(input())
for _ in range(num): # simpler iteration
print("enter the user's name")
name = input("") # in 3.x, this is always a string, so it cannot be None...
# if name == "" or "None,none": # That won't work as you think.
if name == '' or name.lower() == 'none': # but why disallow the string 'None'?
# raise SyntaxError("name cannot be None or empty")
raise RuntimeError("name cannot be None or empty") # or ValueError or alike
# break not needed. raise jumps out without it as well.
user = cls(name, "", "", "", "") # name is an input, not an output.
cls.users.append(name)
但是我想知道这个类是否真的是存储新用户的正确位置，而且只有那些使用此功能创建的用户。也许最好直接在users中提供__init__列表，并让此功能处于更高级别。
在这里使用@classmethod的好处是你总是在相关的基础上工作。
想象一下，如上所述，您拥有UserInput方法__init__()。然后你可以将它子类化并执行
UserInput.create_new_users()使用@classmethod将是最简单的选择。
class UserInputStoring(UserInput):
users = [] # this is only here, not at the parent.
def __init__(self, *a, **k):
super(UserInputStoring, self).__init__(*a, **k) # pass everything up as it was used
self.users.append(self)
现在，您可以在基类中使用create_new_users()并成为@classmethod，然后根据您的调用方式选择正确__init__来调用。