Xpath like query for nested python dictionaries
One of the best libraries I've been able to identify, which, in addition, is very actively developed, is an extracted project from boto: JMESPath. It has a very powerful syntax of doing things that would normally take pages of code to express.
Here are some examples:
search('foo | bar', {"foo": {"bar": "baz"}}) -> "baz"search('foo[*].bar | [0]', { "foo": [{"bar": ["first1", "second1"]}, {"bar": ["first2", "second2"]}]}) -> ["first1", "second1"]search('foo | [0]', {"foo": [0, 1, 2]}) -> [0]
There is an easier way to do this now.
http://github.com/akesterson/dpath-python
$ easy_install dpath>>> dpath.util.search(YOUR_DICTIONARY, "morefoo/morebar")
... done. Or if you don't like getting your results back in a view (merged dictionary that retains the paths), yield them instead:
$ easy_install dpath>>> for (path, value) in dpath.util.search(YOUR_DICTIONARY, "morefoo/morebar", yielded=True)
... and done. 'value' will hold {'bacon': 'foobar'} in that case.
Not exactly beautiful, but you might use sth like
def xpath_get(mydict, path): elem = mydict try: for x in path.strip("/").split("/"): elem = elem.get(x) except: pass return elem
This doesn't support xpath stuff like indices, of course ... not to mention the /
key trap unutbu indicated.