Nesting Dictionary from Word XML

Question

I have a word file with forms in it. The goal is to scan through the XML (with lxml ) and produce a dictionary of {formTag:formValue} . It gets a little more complicated because forms can be nested in other repeating forms which initally produces

{topLevelFormTag:formTag1+formValue1+formTag2+formValue2,  formTag1:formValue1, formTag2:formValue2}

However, the goal is to end up with

{topLevelFormTag:{formTag1:formValue1, formTag2:formValue2}}

As I search through the file ( for field in xmlroot.iter(TAG_FIELD): ) I fill out two dictionaries; parents and descendants with parents[field] = field.getparents( ) and descendants[field] = list(field.iterdescendants()) . Below is my method for collapsing the dictionary of all fields into the a nested dictionary. If there is only one level of nesting, it works fine, however, it fails with additional levels. It fails because a nested form is in the descendants of all the levels above, so it could be placed as a child of any of the upper levels.

for ptag in parents:
    for dtag in descendants:
        if parents[ptag] in descendants[dtag]:
            print "{} is a descendant of {}".format(ptag, dtag)
            try:
                fields[dtag][ptag] = fields[ptag]
                del fields[ptag]
            except TypeError:
                fields[dtag] = {ptag: fields[ptag]}
                del fields[ptag]
            except KeyError:
                print "!!!{}:{}!!!".format(ptag, dtag)

How can I determine the bottom most level to place a field in such that my dictionary is nested correctly?

Answer 1

to find the last nest in any dictionary you have to use recursive relations:

def last_nest(somedict):
    for i in somedict:
        if type(somedict[i]) is dict:
            return last_nest(somedict[i])
    return somedict

test = {"a":{"b":{"c":123}}}
print last_nest(test)

So the main thing you need to think about is how to terminate the recursive relation in order to get the dict that you want at the end.