Python内置函数 eval

eval(source, globals=None, locals=None, /)

In [42]: eval(input("enter two nums:"))
enter two nums:1+2
Out[42]: 3

In [18]: a=1

In [19]: d1={‘a‘:10}

In [21]: print(eval(‘a+1‘,d1))
11

In [23]: print(eval(‘a+1‘))
2

In [4]: a=1

In [5]: b=2

In [6]: c=3

In [7]: d1={‘a‘:4,‘b‘:5}

In [8]: d2={‘b‘:6,‘c‘:7}

In [10]: print(eval(‘a+b+c‘,d1,d2))
17

In [11]: print(eval(‘a+b+c‘,d2,d1))
16