Question

I want to create a function that will create dynamic levels of nesting in a python dictionary.
e.g. if I call my function nesting, I want the outputs like the following:

nesting(1)  :  dict = {key1:<value>}
nesting(2)  :  dict = {key1:{key2:<value>}}
nesting(3)  :  dict = {key1:{key2:{key3:<value>}}}

and so on. I have all the keys and values before calling this function, but not before I start executing the code.

I have the keys stored in a variable ‘m’ where m is obtained from:

m=re.match(pattern,string)

the pattern is constructed dynamically for this case.

Answer 1

You can iterate over the keys like this:

def nesting(level):
    ret = 'value'
    for l in range(level, 0, -1):
        ret = {'key%d' % l: ret}
    return ret

Replace the range(...) fragment with the code which yields the keys in the desired order. So, if we assume that the keys are the captured groups, you should change the function as follows:

def nesting(match): # `match' is a match object like your `m' variable
    ret = 'value'
    for key in match.groups():
        ret = {key: ret}
    return ret

Or use reversed(match.groups()) if you want to get the keys in the opposite order.