I'm trying to find a simple way to convert a string like this:
a = '[[a b] [c d]]'
into the corresponding nested list structure, where the letters are turned into strings:
a = [['a', 'b'], ['c', 'd']]
I tried to use
import ast
l = ast.literal_eval('[[a b] [c d]]')
l = [i.strip() for i in l]
as found here
but it doesn't work because the characters a,b,c,d are not within quotes.
in particular I'm looking for something that turns:
'[[X v] -s]'
into:
[['X', 'v'], '-s']
>>> import json
>>> a = '[[a b] [c d]]'
>>> a = ''.join(map(lambda x: '"{}"'.format(x) if x.isalpha() else x, a))
>>> a
'[["a" "b"] ["c" "d"]]'
>>> json.loads(a.replace(' ', ','))
[[u'a', u'b'], [u'c', u'd']]
This will work with any degree of nested lists following the above pattern, e.g.
>>> a = '[[[a b] [c d]] [[e f] [g h]]]'
>>> ...
>>> json.loads(a.replace(' ', ','))
[[[u'a', u'b'], [u'c', u'd']], [[u'e', u'f'], [u'g', u'h']]]
For the specific example of '[[X v] -s]':
>>> import json
>>> a = '[[X v] -s]'
>>> a = ''.join(map(lambda x: '"{}"'.format(x) if x.isalpha() or x=='-' else x, a))
>>> json.loads(a.replace('[ [', '[[').replace('] ]', ']]').replace(' ', ',').replace('][', '],[').replace('""',''))
[[u'X', u'v'], u'-s']