title: creating new column with values specifying certain values (classifying US states)
body: <p>I'm trying to classify US states into different regions (Northeast, midwest, south, west. df['State'] is the given column in the dataframe and I'm trying to create a new column df['Region'].</p>
  <p>I wrote the following code but all the values showing up in the new column df['Region'] happened to be 'northeast' only.</p>
  <p>Can you advise me what's wrong with my code?</p>
  <pre><code>result = []
  for value in df['State']:
      if value == 'CT' or 'ME' or 'MA' or 'NH' 'RI' or 'VT' or 'NJ' or 'NY' or 'PA':
          result.append('Northeast')
      elif value == 'IL' or 'IN' or 'MI' or 'OH' or 'WI' or 'IA' or 'KS' or 'MN' or 'MO' or 'NE' or 'ND' or 'SD':
          result.append('Midwest')
      elif value == 'AZ' or 'CO' or 'ID' or 'MT' or 'NV' or 'NM' or 'UT' or 'WY' or 'AK' or 'CA' or 'HI' or 'OR' or 'WA':
          result.append('West')
      else:
          result.append('South')
  
  df['Region'] = result
  </code></pre>