title: Pandas: get some data from dataframe
body: <p>I have dataframe <code>ID,"month","type"
  0896cbe25bb8aec86ff93dd1bf20fa80,2013-12,desktop
  0896cbe25bb8aec86ff93dd1bf20fa80,2014-01,desktop
  0896cbe25bb8aec86ff93dd1bf20fa80,2014-02,desktop
  0896cbe25bb8aec86ff93dd1bf20fa80,2014-03,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-06,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-07,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-08,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-09,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-10,desktop
  </code>
  And have another dataframe</p>
  
  <pre><code>idp year    month
  5663b84ee164ed2628f4df6ed6ffe89b    2015    11
  d156e747fb3e715a13ac850ca3e4c0e5    2014    7
  0ce926c4c33e63aeef04a55dc204cb1a    2014    10
  142068cd70ec3541698c919b023caf1c    2014    3
  24fa9c75cc86187937f4fea0c06a6513    2014    12
  3e3906343b235e6eac743be65da1dcbb    2014    6
  757bf2f08a1de8383e24509d5f105ce7    2015    8
  </code></pre>
  
  <p>I need if <code>idp</code> in first dataframe and if date from second df is equal to first (or month from first df less to 1 from second month) I should get data to this ID.
  I need to get</p>
  
  <pre><code>ID, month, type
  0ce926c4c33e63aeef04a55dc204cb1a,2014-06,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-07,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-08,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-09,desktop
  0ce926c4c33e63aeef04a55dc204cb1a,2014-10,desktop
  </code></pre>
  
  <p>How can I write this condition?</p>