title: Comparing two dataframes with a function (without common indices)
body: <p>I have 2 pandas data frames, restaurants:</p>
  
  <pre><code>     Lat        Long             Name
  0    43.599503  1.440678      Le Filochard
  1    43.602369  1.447368      Le Wallace
  2    43.603838  1.435186      Chez Tonton, Pastis Ô Maître
  </code></pre>
  
  <p>and hotels:</p>
  
  <pre><code>      Lat      Long             Name
  0   43.603779  1.444004         Grand Hôtel de l'Opéra
  1   43.599482  1.441207         Hôtel Garonne
  2   43.549924  1.499821         Ibis Styles
  </code></pre>
  
  <p>And 1 function distance(origin,destination) with origin = (lat,long) coord.</p>
  
  <p>I am trying to apply the function to the 2 data frames to calculate for each row of the first data frame the number of item from the second data frame for which the distance is inferior to 0.2 ...</p>
  
  <p>I'm trying the apply map function but do not manage to perform it with the 2 data frames; do I need to merge them?</p>