title: How to pack multilines results (OrderedDict with differents keys) into pandas dataframe?
body: <p>I did a loop over multiple files to get as a result an OrderedDict for each one (possibility to have different keys, which means not the same from an OrderedDict to another). I want to write/ pack the result into the same pandas dataframe. So we will have all the different keys as column names, and each row of the dataframe will represent an OrderedDict.</p>
  
  <p>I have already my results looking like this :</p>
  
  <pre><code>OrderedDict([('mrz_type', 'ID'), ('valid_score', 70), ('valid_composite', False), ('type', 'ID'), ('country', ''), ('number', ''), ('date_of_birth', '840927'), ('sex', 'F'), ('nom', ), ('prenom', ''), ('dep', ''), ('service', '1'), ('office', '056'), ('check_number', '7'), ('check_date_of_birth', '4'), ('check_composite', '9'), ('valid_number', True), ('valid_date_of_birth', True)])
  
  OrderedDict([('mrz_type', 'PASP'), ('valid_score', 62), ('valid_composite', False), ('type', 'P'), ('country', ''), ('number', ''), ('date_of_birth', '550912'), ('expiration_date', '200801'), ('nationality', ''), ('sex', 'M'), ('nom', ''), ('prenom', ''), ('check_number', '2'), ('check_date_of_birth', '9'), ('check_expiration_date', '1'), ('check_composite', '8'), ('valid_number', True), ('valid_date_of_birth', False), ('valid_expiration_date', True)])
  
  OrderedDict([('mrz_type', 'IR'), ('valid_score', 28), ('valid_composite', False), ('type', 'IR'), ('country', ''), ('number', ''), ('date_of_birth', '750612'), ('expiration_date', '010119'), ('nationality', ''), ('sex', 'Z'), ('nom', ''), ('prenom', ''), ('num_etrg', ''), ('check_number', '6'), ('check_date_of_birth', '1'), ('check_expiration_date', ''), ('check_composite', ''), ('valid_number', False), ('valid_date_of_birth', True), ('valid_expiration_date', False)])
  </code></pre>