从字符串解析python嵌套列表

Question

所以我将文件解析为python列表,我遇到了这样的嵌套列表:

{   1   4{  2a  0.0 }{  3   0.0 }{  4c  0.0 }{  5   0.0 }   }

我想把它解释为一个列表,但是嵌套了,所以我希望它成为python列表,如下所示:

[1,4,[2a,0.0],[3,0.0],[4c,0.0],[5,0.0]]

我设法使用以下内容执行正确的字符串:

l = """{    1   4{  2   0.0 }{  3   0.0 }{  4   0.0 }{  5   0.0 }   }"""
l = l.replace("{\t",",[").replace("\t}","]").replace("{","[").replace("}","]").replace("\t",",")[1:]

我也可以申请' l.strip("\t")以便它是一个列表,但不适用于嵌套,否则它将被展平,这是我不想要的.

我尝试过ast.literal_eval(l),但它在字符串上失败,例如2a

Answer 1

Pyparsing有一个内置的帮助器nestedExpr来帮助解析打开和关闭分隔符之间的嵌套列表:

>>> import pyparsing as pp
>>> nested_braces = pp.nestedExpr('{', '}')
>>> t = """{   1   4{  2a  0.0 }{  3   0.0 }{  4c  0.0 }{  5   0.0 }   }"""
>>> print(nested_braces.parseString(t).asList())
[['1', '4', ['2a', '0.0'], ['3', '0.0'], ['4c', '0.0'], ['5', '0.0']]]