title: Trouble converting string to float in python
body: <p>I am fairly new to Python so forgive me this simple question. I'm trying to convert string to float. Here is a sample of the data:</p>
  
  <pre><code>0     10.65%
  1      7.90%
  </code></pre>
  
  <p>When I try:</p>
  
  <pre><code> df['int_rate'] = df['int_rate'].astype('float')
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>ValueError: could not convert string to float: '13.75%'
  </code></pre>
  
  <p>When I try:</p>
  
  <pre><code>df['int_rate'] = df['int_rate'].replace("%","", inplace=True) 
  </code></pre>
  
  <p>And check my data, I get:</p>
  
  <pre><code>0     None
  1     None
  </code></pre>
  
  <p>Any ideas what I'm doing wrong? Many thanks!</p>