情况一: a 直接引用外部的,正常运行 deftoplevel(): a =5defnested(): print(a +2)# theres no local variable a so it prints the nonlocal onenested()returna 情况二:创建local 变量a,直接打印,正常运行 deftoplevel(): a =5defnested(): a =7# create a local variable called a which is d...
python 使用嵌套函数报local variable xxx referenced before assignment或者 local variable XXX defined in enclosing scope 2019-10-14 10:26 −... james_cai 0 4967 Shared variable in python's multiprocessing 2019-12-10 14:19 −Shared variable in python's multiprocessing https://www.programcreek....
嵌套作用域(Enclosing/Enclosing locals) Python中的嵌套作用域(Nested Scope)是变量作用域的一个关键特性,它允许在内部作用域中访问外部作用域(但不是全局作用域)中定义的变量。这种机制使得函数可以访问其封闭作用域(Enclosing Scope)中的变量,而不仅仅是直接定义在它们内部的作用域或全局作用域中的变量。 嵌套作用域...
def func(): local_var = "I am local" print(local_var) func() # 输出 I am local print(local_var) # NameError: name 'local_var' is not defined 在这个例子中,local_var 是函数 func 内部的局部变量,出了这个函数就无法访问。 Enclosing(闭包外层作用域):闭包外层作用域是指嵌套函数中的外部函...
Let's see a simple demo. First of all, define a random string. Then callprintandlenfunction and pass the defined string. >>> slogan = "Life is short, I use Python" >>> print >>> <built-in function print> >>> print(slogan) ...
defa():x=1defb():print(x)# Output: 1a()# NameError: name 'x' is not definedprint(x) 当我们在b函数内部使用x的时候,遵循 LEGB 原则,由于 Local 中没有找到名为x的变量,于是到 Enclosing 中寻找,即函数a所创建的 Scope 中去寻找,然后使用这个处于b函数外层的变量。然而如同上面的例子一样,随着...
def my_function(): local_var = "I am local" print(local_var) # 可以访问 my_function() # 输出: I am local print(local_var) # 报错: NameError: name 'local_var' is not defined 全局作用域(Global Scope): 全局作用域是模块级别的作用域,即在整个模块(Python文件)中都可以访问的变量。 在...
Here,returns a closure that represents aobject. This object has getter and setter functions attached. You can use those functions to get read and write access to the variablesand, which are defined in the enclosing scope and ship with the closure. ...
NameError: name 'i' is not defined 所以,虽然Python没有块级作用域,但是建议就当它有。 不要在代码块以外,使用代码块内定义的东西。 关键字global 前面只是谈及跨作用域的读取,还没谈及跨作用域的写入。 i = 0 def a(): i = 1 print('local:', i) ...
In this case, you’ll get the list of names defined in the function scope: Python >>> def func(): ... var = 100 ... print(dir()) ... another = 200 # Is defined after calling dir() ... >>> func() ['var'] In this example, you use dir() inside func(). When...