title: How to compare two data frames of different size based on a column?
body: <p>I have two data frames with different size</p>
  
  <p>df1</p>
  
  <pre><code>     YearDeci  Year  Month  Day  ...  Magnitude    Lat    Lon  
  0     1551.997260  1551     12   31  ...        7.5  34.00  74.50      
  1     1661.997260  1661     12   31  ...        7.5  34.00  75.00      
  2     1720.535519  1720      7   15  ...        6.5  28.37  77.09      
  3     1734.997260  1734     12   31  ...        7.5  34.00  75.00      
  4     1777.997260  1777     12   31  ...        7.7  34.00  75.00      
  </code></pre>
  
  <p>and </p>
  
  <p>df2</p>
  
  <pre><code>         YearDeci  Year  Month  Day  Hour  ...  Seconds   Mb     Lat     Lon  
  0     1669.510753  1669      6    4     0  ...        0  NaN  33.400  73.200    
  1     1720.535519  1720      7   15     0  ...        0  NaN  28.700  77.200    
  2     1780.000000  1780      0    0     0  ...        0  NaN  35.000  77.000    
  3     1803.388014  1803      5   22    15  ...        0  NaN  30.600  78.600    
  4     1803.665753  1803      9    1     0  ...        0  NaN  30.300  78.800
  5     1803.388014  1803      5   22    15  ...        0  NaN  30.600  78.600.
  </code></pre>
  
  <p>1.I wanted to compare df1 and df2 based on the column 'YearDeci'. and find out the common entries and unique entries(rows other than common rows).</p>
  
  <p>2.output the common rows(with respect to df2) in df1  based on column 'YearDeci'.</p>
  
  <p>3.output the unique rows(with respect to df2) in df1  based on column 'YearDeci'.</p>
  
  <p><strong>*NB: Difference in decimal values up to <em>+/-0.0001</em> in the 'YearDeci' is tolerable</strong></p>
  
  <p>The expected output is like</p>
  
  <p>row_common=</p>
  
  <pre><code>      YearDeci     Year   Month  Day ...   Mb     Lat     Lon 
  2     1720.535519  1720      7   15  ...  6.5  28.37  77.09
  </code></pre>
  
  <p>row_unique=</p>
  
  <pre><code>      YearDeci  Year  Month  Day  ...  Magnitude    Lat    Lon  
  0     1551.997260  1551     12   31  ...        7.5  34.00  74.50      
  1     1661.997260  1661     12   31  ...        7.5  34.00  75.00           
  3     1734.997260  1734     12   31  ...        7.5  34.00  75.00      
  4     1777.997260  1777     12   31  ...        7.7  34.00  75.00 
  </code></pre>