python - 在 Python 函数中，有没有办法在调用方告诉参数的变量名称？

Question

我正在尝试创建一个记录器功能:

def logger(someVariable): 
    # some code that prints the name of someVariable 

所以当我调用函数时:

logger(myvarA)        # should output the string 'myvarA'
logger(someobj.varB)  # should output the string 'someobj.varB'
logger(myarr[3])      # should (probably) output 'myarr[3]'

不确定所有或什至任何这些情况是否可能？用例是在 iPython Notebook 中使用一个简单的函数来记录任何变量的值，而无需键入如下内容:

logger(myVarA,'myVarA')
logger(myarr[i],'myarr[{}]'.format(i))

Answer 1

检查模块( https://docs.python.org/3/library/inspect.html#inspect.getframeinfo )还将为您提供代码上下文。您只需要解析它以获取传递内容的文本。只有一个变量，这很容易做到。这是一个示例。

import inspect
import re

def handle_nested_parens(v):
   parens = 0
   output = ""
   for c in v:
       if c == ")":
           parens = parens - 1
           if parens < 0:
               return output
       output += c
       if c == "(":
           parens = parens + 1
   return output

def logger(v):
   currentframe = inspect.currentframe()
   code_context = inspect.getouterframes(currentframe,1)[1][4][0]
   variable = handle_nested_parens(re.sub(r".*logger\((.*)",r"\1", code_context))
   print("{0} => {1}".format(variable, v))


def testing(a):
   return(a)

def submain(a):
   ab = (1, 2, a)
   logger(testing(ab))
   return 15

def main():
   xyz = "hello"
   logger(xyz)
   logger(submain(xyz))


if __name__ == '__main__':
    a = 5
    logger(a)
    main()

它输出

a => 5
xyz => hello
testing(ab) => (1, 2, 'hello')
submain(xyz) => 15