eval的使用python_python:利用eval来执行字符串代码

接口

eval(str [,globals [,locals ]])函数将字符串str当成有效Python表达式来求值&＃xff0c;并返回计算结果

之前看到eval这个函数时一直想不到需要用的地方&＃xff0c;今天正在研究python属性相关问题时正好用上了&＃xff0c;直接上代码

def func():

f &＃61;1

if __name__ &＃61;&＃61; &＃39;__main__&＃39;:

#打印func的内建属性

print dir(func)

输出如下&＃xff1a;

[&＃39;__call__&＃39;, &＃39;__class__&＃39;, &＃39;__closure__&＃39;, &＃39;__code__&＃39;, &＃39;__defaults__&＃39;, &＃39;__delattr__&＃39;, &＃39;__dict__&＃39;, &＃39;__doc__&＃39;, &＃39;__format__&＃39;, &＃39;__get__&＃39;, &＃39;__getattribute__&＃39;, &＃39;__globals__&＃39;, &＃39;__hash__&＃39;, &＃39;__init__&＃39;, &＃39;__module__&＃39;, &＃39;__name__&＃39;, &＃39;__new__&＃39;, &＃39;__reduce__&＃39;, &＃39;__reduce_ex__&＃39;, &＃39;__repr__&＃39;, &＃39;__setattr__&＃39;, &＃39;__sizeof__&＃39;, &＃39;__str__&＃39;, &＃39;__subclasshook__&＃39;, &＃39;func_closure&＃39;, &＃39;func_code&＃39;, &＃39;func_defaults&＃39;, &＃39;func_dict&＃39;, &＃39;func_doc&＃39;, &＃39;func_globals&＃39;, &＃39;func_name&＃39;]

天啦噜&＃xff0c;一个简单的函数就有这么多内建属性&＃xff0c;于是我想调用print func.call来看看这些属性究竟是什么鬼

但是这么多属性&＃xff0c;不可能一个一个打印的&＃xff0c;于是我想遍历这个列表&＃xff0c;然后不断执行func.attr&＃xff0c;但是遍历出来的attr是字符串啊&＃xff0c;eval出场的时候到了

for attr in dir(func):

print attr, ":", eval("func."&＃43;attr)

输出如下&＃xff0c;可见python私下还是做了很多不知道的东西&＃xff0c;有时间好好研究下这些属性

__call__ :

__class__ :

__closure__ : None

__code__ : None

__delattr__ :

__dict__ : {}

__doc__ : None

__format__ :

__get__ :

__getattribute__ :

__globals__ : {&＃39;son&＃39;: , &＃39;uic&＃39;: , &＃39;main&＃39;: , &＃39;func&＃39;: , &＃39;QtGui&＃39;: , &＃39;parent&＃39;: , &＃39;__builtins__&＃39;: , &＃39;__file__&＃39;: &＃39;C:\\Users\\lht\\Desktop\\\xb1\xcf\xc9\xe8\\test.py&＃39;, &＃39;Des&＃39;: , &＃39;qtCreatorFile&＃39;: &＃39;first.ui&＃39;, &＃39;__package__&＃39;: None, &＃39;sys&＃39;: , &＃39;Ui_MainWindow&＃39;: , &＃39;MyApp&＃39;: , &＃39;__name__&＃39;: &＃39;__main__&＃39;, &＃39;QtBaseClass&＃39;: , &＃39;QtCore&＃39;: , &＃39;__doc__&＃39;: None, &＃39;attr&＃39;: &＃39;__globals__&＃39;}

__hash__ :

__init__ :

__module__ : __main__

__name__ : func

__new__ :

__reduce__ :

__reduce_ex__ :

__repr__ :

__setattr__ :

__sizeof__ :

__str__ :

__subclasshook__ :

func_closure : None

func_code : None

func_dict : {}

func_doc : None

func_globals : {&＃39;son&＃39;: , &＃39;uic&＃39;: , &＃39;main&＃39;: , &＃39;func&＃39;: , &＃39;QtGui&＃39;: , &＃39;parent&＃39;: , &＃39;__builtins__&＃39;: , &＃39;__file__&＃39;: &＃39;C:\\Users\\lht\\Desktop\\\xb1\xcf\xc9\xe8\\test.py&＃39;, &＃39;Des&＃39;: , &＃39;qtCreatorFile&＃39;: &＃39;first.ui&＃39;, &＃39;__package__&＃39;: None, &＃39;sys&＃39;: , &＃39;Ui_MainWindow&＃39;: , &＃39;MyApp&＃39;: , &＃39;__name__&＃39;: &＃39;__main__&＃39;, &＃39;QtBaseClass&＃39;: , &＃39;QtCore&＃39;: , &＃39;__doc__&＃39;: None, &＃39;attr&＃39;: &＃39;func_globals&＃39;}

func_name : func