Python locals()用法及代码示例

locals()Python中的function返回当前本地符号表的字典。

符号表：它是由编译器创建的数据结构，用于存储执行程序所需的所有信息。
本地符号表：该符号表存储了程序本地范围所需的所有信息，并且可以使用python内置函数来访问此信息locals()。

用法： locals()

参数：此函数不接受任何输入参数。

返回类型：这将返回存储在本地符号表中的信息。

范例1：

# Python program to understand about locals 
  
# here no local variable is present 
def demo1():
    print("Here no local variable  is present:", locals()) 
      
# here local variables are present 
def demo2():
     name = "Ankit"
     print("Here local variables are present:", locals()) 
       
# driver code 
demo1() 
demo2()

输出：

Here no local variable  is present: {}
Here local variables are present: {'name':'Ankit'}

范例2：使用更新locals()。

与globals()不同，此函数无法修改本地符号表的数据。下面的程序清楚地说明了这一点。

# Python program to understand about locals 
  
# here no local varible is present 
def demo1():
    print("Here no local variable  is present:", locals()) 
      
# here local variables are present 
def demo2():
     name = "Ankit"
     print("Here local variables are present:", locals()) 
     print("Before updating name is :", name) 
       
     # trying to change name value 
     locals()['name'] = "Sri Ram"
       
     print("after updating name is:", name) 
       
# driver code 
demo1() 
demo2()

输出：

Here no local variable  is present: {}
Here local variables are present: {'name':'Ankit'}
Before updating name is : Ankit
after updating name is: Ankit

范例3： locals() 为全局环境。

在全局环境下，本地符号表与全局符号表相同。

# Python program to understand about locals 
  
# data using locals 
print("This is using locals():", locals()) 
  
# data using globals 
print("This is using globals():", globals())

输出：

This is using locals():{‘__file__’:‘/home/34dde64e1e47944021cdf478b97f13a0.py’, ‘__doc__’:None, ‘__name__’:‘__main__’, ‘__cached__’:None, ‘__spec__’:None, ‘__builtins__’:<module ‘builtins’ (built-in)>, ‘__package__’:None, ‘__loader__’:%lt;_frozen_importlib_external.SourceFileLoader object at 0x7f885e463470>}
This is using globals():{‘__file__’:‘/home/34dde64e1e47944021cdf478b97f13a0.py’, ‘__doc__’:None, ‘__name__’:‘__main__’, ‘__cached__’:None, ‘__spec__’:None, ‘__builtins__’:<module ‘builtins’ (built-in)>, ‘__package__’:None, ‘__loader__’:<_frozen_importlib_external.SourceFileLoader object at 0x7f885e463470>}

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注：本文由纯净天空筛选整理自ankit15697大神的英文原创作品 Python | locals() function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。