title: Convert a Decimal column in pandas into a float column
body: <p>I have the following dataframe:</p>
  
  <pre class="lang-py prettyprint-override"><code>df2 = pd.DataFrame({'price': [Decimal(1.4334), Decimal(1.4335), Decimal(1.4336), Decimal(1.4337)], 'tpo_count': [1, 2, 3, 1], 'tpo': ['A', 'BC', 'BCD', 'D']})
  print(df2.dtypes)
  
  price        object
  tpo_count     int64
  tpo          object
  dtype: object
  </code></pre>
  
  <p>If want ot create an additional column named "price_float" which is the same column as "price" but with floats (to be later draw using matplotlib which does not support Decimal).</p>
  
  <p>I have tried:</p>
  
  <pre><code>df2['price_float']=float(df2['price'])
  </code></pre>
  
  <p>but I get:</p>
  
  <pre><code>TypeError: cannot convert the series to &lt;class 'float'&gt;
  </code></pre>