title: AttributeError: 'Series' object has no attribute 'items'
body: <p>I'm trying to work with a script a colleague wrote.  </p>
  
  <p>This part of the script is working fine:</p>
  
  <pre><code>xl = pd.ExcelFile(path + WQ_file)
  sheet_names = xl.sheet_names
  
  df = pd.read_excel(path + WQ_file, sheetname = 'Chemistry Output Table', skiprows = [0,1,2,4,5,6,7], 
                 index_col = [0,1], na_values = ['', 'na', '-'])
  df.index.names = ['Field_ID', 'Date_Time']
  
  header = pd.read_excel(path + WQ_file, sheetname = 'header data',  
                 index_col = [0], na_values = ['', 'na', ' - '])
  header_dict = {ah: header['name_short'].loc[ah] for ah in header.index}
  
  analytes_excel = pd.read_excel(path + WQ_file, sheetname = 'analytes', columns = 'name')
  analytes_list = [item for sublist in analytes_excel.values.tolist() for item in sublist]
  analytes = [header['name_short'].loc[x] for x in analytes_list]    
  </code></pre>
  
  <p>But this part isn't:</p>
  
  <pre><code># Clean up the data and report "less than" as half of the LOR
  df2 = df.copy()
  for col in df2.columns:
  x = []
  for (a, b) in df2[col].items():
      if b == " - ":
          b = np.nan
      try:
          b = float(b)
      except:
          b = float(b.strip('&lt; '))/2
      x.append(b)
  df2[col] = x
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>---------------------------------------------------------------------------
  AttributeError                            Traceback (most recent call last)
  &lt;ipython-input-4-80ad8c096fc0&gt; in &lt;module&gt;()
    4 for col in df2.columns:
    5     x = []
   ----&gt; 6     for (a, b) in df2[col].items():
    7         if b == " - ":
    8             b = np.nan
  
   C:\Users\SardellaC\AppData\Local\Continuum\Anaconda\lib\site-packages\pandas\core\generic.pyc in __getattr__(self, name)
   1938 
   1939         if name in self._internal_names_set:
  -&gt; 1940             return object.__getattribute__(self, name)
   1941         elif name in self._metadata:
   1942             return object.__getattribute__(self, name)
  
   AttributeError: 'Series' object has no attribute 'items'
  </code></pre>
  
  <p>It might be something to do with different versions of Python used. I'm not familiar at all with Python and would appreciate if someone can point me in the right direction. </p>