title: Filtering dataframe in R based on the condition on last column without hard coding column name
body: <p>Below is my dataframe.</p>
  
  <pre><code>name    m   d1  d2  d3  d4  d5
  name1   m1  45  18  69  35  20
  name2   m2  34  19  16  25  0
  name3   m3  18  38  0   66  29
  name4   m4  52  9   58  84  0
  name5   m5  45  75  76  65  79
  </code></pre>
  
  <p>I would like to get results as shown below. Basically I want to check if the last column has any 0s, then filter only those rows. Please note, I don't want to rely on the column name directly using dollar($) symbol. </p>
  
  <pre><code>name    m   d1  d2  d3  d4  d5
  name2   m2  34  19  16  25  0
  name4   m4  52  9   58  84  0
  </code></pre>