python不能滥用eval python built-in functions 笔记-python-built-in functions-eval,exec,compile 1. python代码执行函数 有时需要动态改变代码,也就是说代码需要是字符串格式,然后在按需要编译,这时,需要一些执行代码的函数,js中的是eval(),python中也有类似内置函数。 1.1. eval函数 函数的作用: 计算指定表达式...
<type 'builtin_function_or_method'>, <type 'instancemethod'>, <type 'function'>, <type 'classobj'>, <type 'dictproxy'>, <type 'generator'>, <type 'getset_descriptor'>, <type 'wrapper_descriptor'>, <type 'instance'>, <type 'ellipsis'>, <type 'member_descriptor'>, <type 'file...
print(eval("abs(-1)"))#By keeping __builtins__":None,eval will recognise no in-buiilt functionprint(eval('abs(-1)',{"__builtins__":None})) 1. OUTPUT:1Traceback (most recent call last): File "main.py", line 1, in print(eval('abs(-1)',{"__builtins__":None})) File ...
print(eval("abs(-1)")) #By keeping __builtins__":None,eval will recognise no in-buiilt function print(eval('abs(-1)',{"__builtins__":None})) OUTPUT: 1 Traceback (most recent call last): File "main.py", line 1, in print(eval('abs(-1)',{"__builtins__":None})) File...
(built-in)>,'func':<functionfunc at0x000001F048C5E048>,'__doc__':None,'__file__':'C:/Users/wader/PycharmProjects/LearnPython/day04/func5.py','__loader__':<_frozen_importlib_external.SourceFileLoader object at0x000001F048BF4C50>,'__spec__':None,'age':18,'__name__':'__...
File"/Users/liuhuiling/Desktop/MT_code/OpAPIDemo/conf/OPCommUtil.py", line 39,in<module>res= getattr(functiondemo,"age") AttributeError:'function_demo'object has no attribute'age'getattr(functiondemo,"age", 18)#获取不存在的属性,返回一个默认值 ...
python语言里的eval()是属于python的builtin_function,它的实现是在builtin_eval staticPyObject *builtin_eval(PyObject *module, PyObject *const*args, Py_ssize_t nargs){ PyObject *return_value =NULL; PyObject *source; PyObject *globals = Py_None; ...
This function can also be used to execute arbitrary code objects (such as those created by compile()). In this case pass a code object instead of a string. If the code object has been compiled with 'exec' as the mode argument, eval()‘s return value will be None. ...
eval(str)函数很强大,官方解释为:将字符串str当成有效的表达式来求值并返回计算结果。所以,结合math当成一个计算器很好用。 eval()函数常见作用有: 注意要用字符串表示一个计算式 1、计算字符串中有效的表达式,并返回结果 >>> eval('pow(2,2)')
This function can also be used to execute arbitrary code objects (such as those created by compile()). In this case pass a code object instead of a string. If the code object has been compiled with 'exec' as the mode argument, eval()‘s return value will be None.Hints: dynamic ...