title: 'float' object has no attribute 'strip'
body: <p>I want to clean one column of my df['emp_length']
  [shown in the screen shot]<a href="https://i.stack.imgur.com/yzBHG.png" rel="noreferrer">1</a></p>
  
  <p>but when I use </p>
  
  <pre><code>df_10v['emp_length'] = df_10v['emp_length'].map(lambda x: x.lstrip('&lt;').rstrip('+'))
  </code></pre>
  
  <p>to remove thing i dont want. It gave me an error:</p>
  
  <pre><code>'float' object has no attribute 'lstrip'
  </code></pre>
  
  <p>However, the type shows object instead of float.
  I tried .remove too but gave me the same error. 
  I also tried </p>
  
  <pre><code>df['column'] = df['column'].astype('str') 
  </code></pre>
  
  <p>to change df_10v['emp_length'] in to string and then strip, but it does not work either. Anybody know how to solve this? Thank you!</p>