On Thu, 18 Feb 2010 00:13:05 +0000, Rhodri James wrote: > On Wed, 17 Feb 2010 23:48:38 -0000, Wes James <compte...@gmail.com> > wrote: > >> I have been trying to create a list form a string. The string will be >> a list (this is the contents will look like a list). i.e. "[]" or >> "['a','b']" > > If your string is trusted (i.e. goes nowhere near a user), just eval() > it.
Or use something like YAML or JSON to parse it. Fredrik Lundh has a simple_eval function which should be safe to use: http://effbot.org/zone/simple-iterator-parser.htm But it's fairly simple to parse a simple list like this. Here's a quick and dirty version: def string_to_list(s): s = s.strip() if not s.startswith('[') and s.endswith(']'): raise ValueError s = s[1:-1].strip() items = [item.strip() for item in s.split(',')] for i, item in enumerate(items): items[i] = dequote(item) return items def dequote(s): for delimiter in ('"""', "'''", '"', "'"): if s.startswith(delimiter) and s.endswith(delimiter): n = len(delimiter) return s[n:-n] raise ValueError >>> s = "['a','b']" >>> print s ['a','b'] >>> string_to_list(s) ['a', 'b'] >>> x = string_to_list(s) >>> type(x) <type 'list'> >>> x ['a', 'b'] -- Steven -- http://mail.python.org/mailman/listinfo/python-list
