python字符串如何定义,如何使用python从一个字符串定义一个函数

this is my code :

a &＃61; \

&＃39;&＃39;&＃39;def fun():\n

print &＃39;bbb&＃39;

&＃39;&＃39;&＃39;

eval(a)

fun()

but it shows error :

Traceback (most recent call last):

File "c.py", line 8, in

eval(a)

File "", line 1

def fun():

^

SyntaxError: invalid syntax

so what can i do ,

thanks

解决方案

eval() with string a string argument is only for expressions. If you want to execute statements, use exec:

exec """def fun():

print &＃39;bbb&＃39;

"""

But before you do that, think about whether you really need dynamic code or not. By far most things can be done without.