title: AttributeError: 'list' object has no attribute 'strip'
body: <p>The following code is causing AttributeError: 'list' object has no attribute 'strip' and I do not how to fix it:</p>
  
  <pre><code>#!/usr/bin/env python
  from __future__ import absolute_import, division, print_function
  from itertools import groupby
  
  
  DATA = [["Test", "A", "B01", 828288,  1,    7, 'C', 5],
          ["Test", "A", "B01", 828288,  1,    7, 'T', 6],
          ["Test", "A", "B01", 171878,  3,    7, 'C', 5],
          ["Test", "A", "B01", 171878,  3,    7, 'T', 6],
          ["Test", "A", "B01", 871963,  3,    9, 'A', 5],
          ["Test", "A", "B01", 871963,  3,    9, 'G', 6],
          ["Test", "A", "B01", 1932523, 1,   10, 'T', 4],
          ["Test", "A", "B01", 1932523, 1,   10, 'A', 5],
          ["Test", "A", "B01", 1932523, 1,   10, 'X', 6],
          ["Test", "A", "B01", 667214,  1,   14, 'T', 4],
          ["Test", "A", "B01", 667214,  1,   14, 'G', 5],
          ["Test", "A", "B01", 667214,  1,   14, 'G', 6]]
  
  
  def iter_something(rows):
      key_names = ['type', 'name', 'sub_name', 'pos', 's_type', 'x_type']
      chr_key_names = ['letter', 'no']
      for keys, group in groupby(rows, lambda row: row[:6]):
          result = dict(zip(key_names, keys))
          result['chr'] = [dict(zip(chr_key_names, row[6:])) for row in group]
          yield result
  
  
  def convert(val):
      constructors = [int, str]
      for c in constructors:
          try:
              return c(val)
          except ValueError:
              pass
  
  
  def main():
      with open("/home/mic/tmp/test.txt") as f:
          parts = (line.split(',') for line in f)
          column = (part.strip() for part in parts)
          for object_ in iter_something(column):
              print(object_)
  
  
  if __name__ == '__main__':
      main()
  </code></pre>