title: pandas two dataframe cross join
body: <p>I can't find anything about cross join include the  merge/join or some other.
  I need deal with two dataframe using {my function} as  myfunc .
  the equivalent of :</p>
  
  <pre><code>{
      for itemA in df1.iterrows():
             for itemB in df2.iterrows():
                         t["A"] = myfunc(itemA[1]["A"],itemB[1]["A"])
   }      
  </code></pre>
  
  <p>the equivalent of :</p>
  
  <pre><code>{
   select myfunc(df1.A,df2.A),df1.A,df2.A from df1,df2;
  }
  </code></pre>
  
  <p>but I need more efficient solution:
  if used apply i will  be how to implement them  thx;^^</p>