title: finding a user with maximum degree centrality score within a larger network of users in wiki articles
body: <p>Hi I am having a problem where i want to make a network of user based on articles in a data frame named "wiki" like 
   Faid  users1   users2      ( Faid= articles), users1= network node,users2= network node)
    1      a1       u1
    1      a1       a2
    .      a1       b2
    .      u1       a2
    .      u1       b2
    1      a2       b2</p>
  
  <p>2      a1       c1
    .      a1       a2
    .      a1       c2
    .      c1       a2
    .      c1       c2
    2      a2       c2</p>
  
  <p>3     c2        c1
    .     c2        u2
    .     c2        u1
    .     c1        u2
    .     c1        u1
    3     u2        u1</p>
  
  <p>this is just a an example I have more than  3000 article's user networks .
   what I want is to find the degree centrality scor for each user in a whole network( in all article) and shows the score in a column where (Faid 1 )have a centrality score of a user with highest degree centrality score and (Faid 2) have the highest degree centrality score .
   but the score should be of a user that belong to the network of that article. e.g
  users      centrality_score
  a1              100
  a2              80
  b1              70
  b2              55
  c1              10
  c2              50
  u1              140
  u2              15
  and the final dataframe would look like this 
  Faid         centrality score<br>
  1              140    (# i.e. u1 has 140)
  2              100
  3              140
  this is just an example of the data I have and the results I want. any help would highly be appreciated. thanks</p>