Python 如何声明类属性的类型？

如何声明类属性类型？例如，在下面的类中，如何将

self.number

声明为

unsinged int

类型

正在尝试以这种方式声明它：

class A:    

    def __init__(self):
        cdef unsigned int self.number
        self.number = 4
        print(type(self.number), self.number)

导致此错误的原因：

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-34-80176274b668> in <module>
----> 1 get_ipython().run_cell_magic('cython', '', 'class A:    \n    \n    def __init__(self):\n        cdef unsigned int self.number\n        self.number = 4\n        print(type(self.number), self.number)\n')

~/anaconda3/lib/python3.7/site-packages/IPython/core/interactiveshell.py in run_cell_magic(self, magic_name, line, cell)
   2321             magic_arg_s = self.var_expand(line, stack_depth)
   2322             with self.builtin_trap:
-> 2323                 result = fn(magic_arg_s, cell)
   2324             return result
   2325 

<decorator-gen-127> in cython(self, line, cell)

~/anaconda3/lib/python3.7/site-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
    185     # but it's overkill for just that one bit of state.
    186     def magic_deco(arg):
--> 187         call = lambda f, *a, **k: f(*a, **k)
    188 
    189         if callable(arg):

~/anaconda3/lib/python3.7/site-packages/Cython/Build/IpythonMagic.py in cython(self, line, cell)
    323         if need_cythonize:
    324             extensions = self._cythonize(module_name, code, lib_dir, args, quiet=args.quiet)
--> 325             assert len(extensions) == 1
    326             extension = extensions[0]
    327             self._code_cache[key] = module_name

TypeError: object of type 'NoneType' has no len()

它会导致以下错误：

Error compiling Cython file:
------------------------------------------------------------
...
class A:
    cdef unsigned int number
        ^
------------------------------------------------------------

/home/greg/.cache/ipython/cython/_cython_magic_48a1f134ce2732274c6f5bdb1c477e52.pyx:2:9: cdef statement not allowed here

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-35-0af4c38224f5> in <module>
----> 1 get_ipython().run_cell_magic('cython', '', 'class A:\n    cdef unsigned int number\n    \n    def __init__(self):\n        self.number = 4\n        print(type(self.number), self.number)\n')

~/anaconda3/lib/python3.7/site-packages/IPython/core/interactiveshell.py in run_cell_magic(self, magic_name, line, cell)
   2321             magic_arg_s = self.var_expand(line, stack_depth)
   2322             with self.builtin_trap:
-> 2323                 result = fn(magic_arg_s, cell)
   2324             return result
   2325 

<decorator-gen-127> in cython(self, line, cell)

~/anaconda3/lib/python3.7/site-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
    185     # but it's overkill for just that one bit of state.
    186     def magic_deco(arg):
--> 187         call = lambda f, *a, **k: f(*a, **k)
    188 
    189         if callable(arg):

~/anaconda3/lib/python3.7/site-packages/Cython/Build/IpythonMagic.py in cython(self, line, cell)
    323         if need_cythonize:
    324             extensions = self._cythonize(module_name, code, lib_dir, args, quiet=args.quiet)
--> 325             assert len(extensions) == 1
    326             extension = extensions[0]
    327             self._code_cache[key] = module_name

TypeError: object of type 'NoneType' has no len()

编译Cython文件时出错： ------------------------------------------------------------ ... A类： 无符号整数 ^ ------------------------------------------------------------ /home/greg/.cache/ipython/cython/\u cython\u magic\u 48a1f134ce27274c6f5bdb1c47e52.pyx:2:9:cdef语句此处不允许 --------------------------------------------------------------------------- TypeError回溯（最近一次调用上次） 在里面 ---->1获取\u ipython（）。运行\u cell\u magic（'cython'，''，类A:\n cdef无符号整数编号\n\n def \uuuuuuuuu init\uuuuuuuu（self）：\n self.number=4\n打印（类型（self.number），self.number）\n'） ~/anaconda3/lib/python3.7/site-packages/IPython/core/interactiveshell.py in run\u cell\u magic（self，magic\u name，line，cell） 2321 magic_arg_s=self.var_expand（行、堆栈深度） 2322带自建存水弯： ->2323结果=fn（魔法参数，单元格） 2324返回结果 2325 在cython中（自身、线、单元） ~/anaconda3/lib/python3.7/site-packages/IPython/core/magic.py in（f，*a，**k） 185#但就这一点来说就太过分了。 186 def魔术装饰（arg）： -->187调用=λf，*a，**k:f（*a，**k） 188 189如果可调用（arg）： Cython中的~/anaconda3/lib/python3.7/site-packages/Cython/Build/IpythonMagic.py（self、line、cell） 323如有需要，请： 324 extensions=self.\u cythonize（模块名称、代码、库目录、args、quiet=args.quiet） -->325断言长度（扩展）==1 326扩展=扩展[0] 327 self.\u code\u cache[key]=模块名称 TypeError:类型为“NoneType”的对象没有len（）

---

如何为Python类声明属性类型？

为什么文档（）中的第一个示例不是您的选项？@ead该类需要可以从Python访问，

cdef类

似乎不允许这样做OK，您的问题还不清楚。文档中的第二个示例如何：？@ead谢谢，我想这就是答案，在cython中对cdef类进行子类化可能的重复，为什么文档中的第一个示例（）不是您的选项？@ead该类需要可以从Python访问，并且

cdef类

似乎不允许这样做OK，你的问题不清楚。文档中的第二个示例如何：？@ead谢谢，我想这就是答案，在cython中对cdef类进行子类化可能是的副本

Error compiling Cython file:
------------------------------------------------------------
...
class A:
    cdef unsigned int number
        ^
------------------------------------------------------------

/home/greg/.cache/ipython/cython/_cython_magic_48a1f134ce2732274c6f5bdb1c477e52.pyx:2:9: cdef statement not allowed here

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-35-0af4c38224f5> in <module>
----> 1 get_ipython().run_cell_magic('cython', '', 'class A:\n    cdef unsigned int number\n    \n    def __init__(self):\n        self.number = 4\n        print(type(self.number), self.number)\n')

~/anaconda3/lib/python3.7/site-packages/IPython/core/interactiveshell.py in run_cell_magic(self, magic_name, line, cell)
   2321             magic_arg_s = self.var_expand(line, stack_depth)
   2322             with self.builtin_trap:
-> 2323                 result = fn(magic_arg_s, cell)
   2324             return result
   2325 

<decorator-gen-127> in cython(self, line, cell)

~/anaconda3/lib/python3.7/site-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
    185     # but it's overkill for just that one bit of state.
    186     def magic_deco(arg):
--> 187         call = lambda f, *a, **k: f(*a, **k)
    188 
    189         if callable(arg):

~/anaconda3/lib/python3.7/site-packages/Cython/Build/IpythonMagic.py in cython(self, line, cell)
    323         if need_cythonize:
    324             extensions = self._cythonize(module_name, code, lib_dir, args, quiet=args.quiet)
--> 325             assert len(extensions) == 1
    326             extension = extensions[0]
    327             self._code_cache[key] = module_name

TypeError: object of type 'NoneType' has no len()