Python-Json Parser

Question

I am trying to implement python Json parser with the following set of rules:

Rule 1:

A JSON data object always begins with curly braces and ends with curly braces. {}

Rule 2:

All data is represented in the form of

"string":value

where the value can be any of the following:

• number
• string
• boolean
• another json

Rule 3:

The rules for forming the strings (on the left hand side in red) are similar to rules for variables in most programming languages.
* They can be alphanumeric, but should always begin with a letter.
* They are case sensitive
* They can not contain special characters except underscores.

I worked on it and completed all the conditions except "another json". Hee is my code

import re
import string
class parser(object):

    fp=open('jsondata.txt','r')
    str=fp.read()
    def __init__(self):
        print "Name of the file Opened is :",self.fp.name 
        print "Contents of the file :\n",self.str
    def rule1(self,str):

        if self.str[:1].startswith('{'):
            if self.str[:-1].endswith('}'):
                print "RULE 1\n",
                print "first character is '{' last character is '} : passed rule1\n"
        else:
            print "Not a JSON data"
    def splitdata(self):
        self.str=self.str[1:]
        self.str=self.str[:-2]
        print self.str
        #Storing the words of string in a list
        self.list1=[]
        self.list1=re.split(',',self.str)
        self.list2=[]
        self.list3=[]
        for i in self.list1:
            self.list2=list(re.split(':',i))
            self.list3.extend(list(self.list2))
        self.left_list=[]
        self.right_list=[]
        self.i=0
        self.left_list=list([self.list3[i] for i in range(len(self.list3)) if i % 2 == 0])
        self.right_list=list([self.list3[i] for i in range(len(self.list3)) if i % 2 == 1])
        print "DATA SPLIT"
        print "Left elements of the json data:",self.left_list
        print "Right elements of the json data:",self.right_list,"\n"

    def left_parse(self):

        """we gona check "This part of the string":"This part will be checked in next function"\
        Conditions imposed on left part of string:\
        1.starts and ends with ""\
        2.Starts with Alphabet\
        3.Contains No special characters except unserscore _""" 

        for i in range(len(self.left_list)):
            self.str1=self.left_list[i]
            if self.str1.startswith('"') and self.str1.endswith('"')\
                and self.str1[1].isalpha():
                self.str2=self.str1[1:]
                self.str3=self.str2[:-1]
                print "Left side content:",self.str3
                print  "Status : Valid"if re.match("^[a-zA-Z0-9_]*$", self.str3) else "Invalid"
            else:
                print "Left side content:",self.str1
                print "Status: Invalid" 






obj=parser()
obj.rule1(str)
obj.splitdata()
obj.left_parse()    

Now the problem is When i tried to check my right_list, whenever i get Another json data then the output goes wild. Can anyone please help me. i framed left_list and right_list based on splitting(comma and colon).
While parsing json inside a json this logic seems not working...