Building and Transvering multi-level dictionaries

[Darrell]

[Lee Joramo]
> I am trying to build a multi-level dictionary from an text file, and
> then transverse the dictionary, create formated output. I have been
> able to do this for a special case where ever piece of data has a fixed
> number of levels (sub-catagories). However, I am looking for an method
> that can elegantly handel a dictionary with variable depth.
>
Hope this helps.



import pprint
import re, string

dat="""
animal:mammal:dog             A very lazy dog
animal:mammal:dog             Super hunting dog
animal:mammal:dog             Not your average hound
animal:mammal:cat             Enjoys sleeping in the sun
animal:snake                  Beware of the python in the forest
animal:fish                   There are many fish in the deep blue sea
animal:fish                   Tuna terrorize the oceans
plant:tree:evergreen:redwood  Very Very Very Tall
"""

def _buildDic(keyList, val, dic):
    """
    If performance became a problem this function
    would benifit from stackless python.

http://x41.deja.com/getdoc.xp?AN=579586064&CONTEXT=953604693.1731985442&hitn
um=9
    """
    if len(keyList)==1:
        dic[keyList[0]]=val
        return

    newDic=dic.get(keyList[0],{})
    dic[keyList[0]]=newDic
    _buildDic(keyList[1:], val, newDic)


def buildDic(buf, dic=None):
    """
    """
    if dic==None:
        dic={}

    lines= string.split(buf,'\n')
    for l in lines:
        key=string.split(l)
        if len(key) < 2:
            continue
        keyList=string.split(key[0],':')
        _buildDic(keyList,string.join(key[1:]),dic)

    return dic

def lookUp(dic,key):
    """
    """
        # Not sure about using "." and ":" for separators
    keys=string.split(key,'.')
    val=dic
    for k in keys:
        val= val[k]
    return val


dataDic=buildDic(dat)
pprint.pprint(dataDic)
print
print lookUp(dataDic,'animal.mammal.cat')


######### output
"""
{'animal': {'fish': 'Tuna terrorize the oceans',
            'mammal': {'cat': 'Enjoys sleeping in the sun',
                       'dog': 'Not your average hound'},
            'snake': 'Beware of the python in the forest'},
 'plant': {'tree': {'evergreen': {'redwood': 'Very Very Very Tall'}}}}

Enjoys sleeping in the sun
"""