python - 将字符串转换为正数和负数列表

Question

如果我有一个始终采用 'a,b,c,d,e' 形式的字符串，其中字母是正数或负数，例如 '1,-2,3 ,4,-5' 并且我想将它变成元组，例如 (1,-2,3,4,-5)，我该怎么做？

Answer 1

一种方法是使用 ast.literal_eval :

Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.

This can be used for safely evaluating strings containing Python expressions from untrusted sources without the need to parse the values oneself.

>>> import ast
>>> ast.literal_eval('1,-2,3,4,-5')
(1, -2, 3, 4, -5)