Pymongo not parsing like JSON

I have a JSON doc like the following:

x = {'ALPHA':{'A':{ 'T1':{ 'L':{'a':1,
                                    'b':2,
                                    'c':3,},

                                'S':{'a':1,
                                     'b':2,
                                     'c':3,}},

                        'T2':{'L':{'a':1,
                                   'b':2,
                                   'c':3,},

                               'S':{'a':1,
                                    'b':2,
                                    'c':3,}},

                        'T3':{'L':{'a':1,
                                    'b':2,
                                    'c':3,},

                               'S':{'a':1,
                                    'b':2,
                                    'c':3,}}
                        }
              }
     }

Where I can parse normally getting 'A', with a standard x['ALPHA']['A']. I thought the mongoDB equivalent would be mongo.find_one({'ALPHA':'A'}), but I am confused about this. Maybe I am creating the documents incorrectly?

Here is the case:

import pymongo

mong  =  pymongo.Connection()['ALPH']['AZ']

letter_dict = ('A','B','C','D')
for letter in letter_dict:
    x = {'ALPHA':{letter :{ 'T1':{ 'L':{'a':1,
                                        'b':2,
                                        'c':3,},

                                    'S':{'a':1,
                                         'b':2,
                                         'c':3,}},

                            'T2':{'L':{'a':1,
                                       'b':2,
                                       'c':3,},

                                   'S':{'a':1,
                                        'b':2,
                                        'c':3,}},

                            'T3':{'L':{'a':1,
                                        'b':2,
                                        'c':3,},

                                   'S':{'a':1,
                                        'b':2,
                                        'c':3,}}
                            }
                  }
         }

    mong.insert(x)

But when I try searching for 'A', It is either finding None, or returning a cursor, or an object id:

mong.find_one({'ALPHA':'A'})
>>>None
mong.find_one({},{'A':1})
>>>{u'_id': ObjectId('55f2eeb7c8b582120834de8f')}

Can someone give a hand?

via Chebli Mohamed