eval与ast.literal_eval

Posted 2021-03-04 cxms

原文：https://blog.csdn.net/sun2333/article/details/82418326

1、eval可以字符串型的list,tuple,dict转变成原有的类型

（1）string <=> list

In [1]: s = ‘[1, 2, 3, 4]‘

In [2]: l = eval(s)

In [3]: s
Out[3]: ‘[1, 2, 3, 4]‘

In [4]: l
Out[4]: [1, 2, 3, 4]

In [5]: type(s)
Out[5]: str

In [6]: type(l)
Out[6]: list

（2）string <=> tuple

In [9]: s = ‘(1, 2, 3)‘

In [10]: l = eval(s)

In [11]: s
Out[11]: ‘(1, 2, 3)‘

In [12]: l
Out[12]: (1, 2, 3)

In [13]: type(s)
Out[13]: str

In [14]: type(l)
Out[14]: tuple

（3）string <=> dict

In [15]: s = "{‘key‘: ‘value‘}"

In [16]: d = eval(s)

In [17]: s
Out[17]: "{‘key‘: ‘value‘}"

In [18]: d
Out[18]: {‘key‘: ‘value‘}

In [19]: type(s)
Out[19]: str

In [20]: type(d)
Out[20]: dict

2、ast.literal_eval：则会判断需要计算的内容计算后是不是合法的python类型，如果是则进行运算，否则就不进行运算

只会执行合法的python类型，会降低系统风险