[英]Function annotation in python 3 get “name not defined” error
I am trying to use python3 type annotation features. 我正在尝试使用python3类型注释功能。
Here is some toy functions without annotation: 这是一些没有注释的玩具功能:
def fa(func, *args):
return func(*args)
def fb(x:str):
return x + " returned."
fa(fb, "Newton")
These work ok. 这些工作正常。 But once I add some annotation for
fa
, it goes awry: 但是,一旦我为
fa
添加了一些注释,它就会出错:
def fa(func:function, *args):
return func(*args)
def fb(x:str):
return x + " returned."
fa(fb, "Newton")
Traceback (most recent call last):
File "/usr/local/lib/python3.4/site-packages/IPython/core/interactiveshell.py", line 2883, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-17-193b74f82e47>", line 1, in <module>
def fa(func:function, *args):
NameError: name 'function' is not defined
Why is this happening and how can I work around it? 为什么会发生这种情况,我该如何解决?
As the error message tells you, the name function
isn't defined. 如错误消息所示,未定义名称
function
。 If you want to hint as a function, put it in quotes: 如果要将提示作为函数,请将其用引号引起来:
def fa(func: 'function', *args):
Because you define a variable in function parameters,but that parameter is not exist out of function.You have to write 因为您在函数参数中定义了一个变量,但是该参数在函数外并不存在。您必须编写
fa(function="Newton")
FA(功能= “牛顿”)
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