title: data frame check if the condition is matching with correspond value
body: <p>Let's say I have a data frame like:</p>
  
  <pre><code>    print(df)
  
      category size
      large 100
      small 10
      medium 50
      small 10
      medium 40
      large 120
  </code></pre>
  
  <p>I want to check between category and size whether the size has the exact value corresponding to the category.</p>
  
  <pre><code>large == 100, medium == 50 and small == 10.
  </code></pre>
  
  <p>I want to use given below syntax:</p>
  
  <pre><code>for df_index, df_line in df.iterrows():
  </code></pre>
  
  <p>And if a line has mismatching, then leave that line, otherwise, drop a well-matched line.
  The output should be like:
          print(df)</p>
  
  <pre><code>    category size
      medium 40
      large 120
  </code></pre>