title: Best way to extract value from pandas dataframe for mathematical operations
body: <p>Say I want to find a value (<code>value_wanted</code>) located under a specific column (<code>col</code>) of a dataframe (<code>df</code>) and is found based on some criteria (<code>df['A']==cond1</code>) and use that value to multiply/add/subtract/etc something.</p>
  
  <p>Right now I'm obtaining the value like this:</p>
  
  <pre><code>value_wanted = df.iloc[:,col][(df['A']==cond1)].reset_index(drop=True).iat[0]
  important_stff = value_wanted * 1000
  </code></pre>
  
  <p>So value I want is located in the <code>col</code> column of <code>df</code>, but the row is determined by the <code>df['A'] == cond1</code></p>
  
  <p>If it helps, I would do this in Excel <code>=index(df!A:Z, match(cond1, df!A:A,0)),col)</code></p>
  
  <p>Is there a better/cleaner of way obtaining just the value from a dataframe?</p>