Python 3 exec method : NameError: name of a defined function is not defined

Question

工人档案：vir.py

def calcCycleOffset():
    global cycleOffset, uc, cs

    cycleOffset = uc - cs
    return cycleOffset


def vir_main():
    calcCycleOffset()


vir_main()
#calcCycleOffset()


print( "vir.py: cycleOffset: ", cycleOffset )

执行器文件：exec.py

filename = "./vir.py"
vir_globals = { "uc": 42, "cs": 12, "cycleOffset": -1 }

with open(filename, "rb") as source_file:
    code = compile(source_file.read(), filename, "exec")

exec(code, vir_globals, {} )

print( 'exec: globals.cycleOffset', vir_globals['cycleOffset'] )

此模式失败：

Traceback (most recent call last):
  File "exec.py", line 7, in <module>
    exec(code, vir_globals, {} )
  File "./vir.py", line 12, in <module>
    vir_main()
  File "./vir.py", line 9, in vir_main
    calcCycleOffset()
NameError: name 'calcCycleOffset' is not defined

但是，python 知道函数 calcCycleOffset()。如果您将 vir.py 中的评论从：

切换为

vir_main()
#calcCycleOffset()

至：

#vir_main()
calcCycleOffset()

那么函数调用就OK了

我希望能够在 vir.py 文件的函数中嵌套函数，并且仍然能够动态地执行它...

求助！

谢谢

Answer 1

如官方文档中关于 locals 对象的解释：https://docs.python.org/3.8/library/functions.html#locals

Note : The contents of this dictionary should not be modified; changes may not affect the values of local and free variables used by the interpreter.

并且您作为本地对象向此处传递了一个空对象。

在您的执行程序文件中请将您的代码更改为：

filename = "./vir.py"
vir_globals = { "uc": 42, "cs": 12, "cycleOffset": -1 }

with open(filename, "rb") as source_file:
    code = compile(source_file.read(), filename, "exec")

exec(code, vir_globals) #remove the empty object here !!

print( 'exec: globals.cycleOffset', vir_globals['cycleOffset'] )

它应该是技巧

你也可以看看这个问题和@thefourtheye 的精彩回答 Using a function defined in an exec'ed string in Python 3

Python 3 exec method : NameError: name of a defined function is not defined

Python 3 exec method : NameError: name of a defined function is not defined

exec

dynamic-programming

python-3.x

工人档案：vir.py

执行器文件：exec.py