title: Value Error: object of too small depth for desired array
body: <p>I want to correlate s1 and s2 variables in my zip_list. However, I have this error:</p>
  
  <p>"return multiarray.correlate2(a, v, mode)
  ValueError: object of too small depth for desired array"</p>
  
  <p>Is there anyone who could help me?</p>
  
  <hr>
  
  <pre><code>s1 = [] 
  s2 = []
  date = []
  
  for f in files:
      with open(f) as f:
      f.next()
      rows = csv.reader(f)
      for row in rows:
          item_list = []
          for row_item in row:
              output_string = map(lambda x: '0' if x=='NULL' else x, row_item.split(","))
              item_list.append(output_string)
          date = item_list[0]
          s1 = item_list[2]
          s2 = item_list[3]
  
          zip_list = []
          for x, y in zip(s1, s2):
              pos = {"s1": x, "s2": y}
              zip_list.append(pos)
              print zip_list
  
          for line in zip_list:
              print np.correlate(x,y)
  
  
      input values:
  
      s1: ['113']
          ['116']
          ['120']
          ['120']
          ['117']
          ['127']
          ['124']
          ['118']
          ['124']
          ['128']
          ['128']
          ['125']
          ['112']
          ['122']
          ['125']
          ['133']
          ['128']
  
          s2: ['125']
          ['123']
          ['120']
          ['115'] 
          ['124']
          ['120']
          ['120']
          ['119']
          ['119']
          ['122']
          ['121']
          ['116'] 
          ['116']
          ['119']
          ['116']
          ['113']
  
          zip_list: [{'s2': '114', 's1': '52'}]
          [{'s2': '114', 's1': '52'}]
          [{'s2': '121', 's1': '67'}]
          [{'s2': '121', 's1': '67'}]
          [{'s2': '124', 's1': '72'}]
          [{'s2': '124', 's1': '72'}]
          [{'s2': '124', 's1': '76'}]
          [{'s2': '124', 's1': '76'}]
          [{'s2': '122', 's1': '80'}]
          [{'s2': '122', 's1': '80'}]
          [{'s2': '115', 's1': '74'}]
          [{'s2': '115', 's1': '74'}]
          [{'s2': '114', 's1': '69'}]
          [{'s2': '114', 's1': '69'}]
          [{'s2': '115', 's1': '64'}]
          [{'s2': '115', 's1': '64'}]
          [{'s2': '111', 's1': '63'}]
          [{'s2': '111', 's1': '63'}]
          [{'s2': '112', 's1': '56'}]
          [{'s2': '112', 's1': '56'}]
          [{'s2': '116', 's1': '49'}]
          [{'s2': '116', 's1': '49'}]
          [{'s2': '119', 's1': '54'}]
          [{'s2': '119', 's1': '54'}]
          [{'s2': '119', 's1': '54'}]
  </code></pre>