title: openpyxl copy from one workbook to another
body: <p>I am trying to copy the cells from one workbook to another, to do some manipulation. While i am able to assign style/value and assign it to new workbook i am unable to assign the font,fill from the existing workbook to new workbook.
  Below is the snippet of my code</p>
  
  <pre><code>from openpyxl import load_workbook
  from openpyxl import Workbook
  File = load_workbook(filename='testcopy.xlsx')
  FileSheets = File.get_sheet_names()
  AcSheet = File.active
  
  write_file = Workbook()
  wr_ac_sheet = write_file.active
  wr_ac_sheet['A1'].value = AcSheet['A1'].value
  wr_ac_sheet['A1'].style = AcSheet['A1'].style
  write_file.save('copied_excel.xlsx')
  </code></pre>
  
  <p>This works fine, but if i use </p>
  
  <pre><code>wr_ac_sheet['A1'].font= AcSheet['A1'].font
  </code></pre>
  
  <p>i get the below error</p>
  
  <pre><code> File "C:\Python27\lib\site-packages\openpyxl\writer\excel.py", line 90, in write_data
  stylesheet = write_stylesheet(self.workbook)
  File "C:\Python27\lib\site-packages\openpyxl\styles\stylesheet.py", line 206, in write_stylesheet
  stylesheet.fonts = wb._fonts
  File "C:\Python27\lib\site-packages\openpyxl\descriptors\sequence.py", line 27, in __set__
  seq = [_convert(self.expected_type, value) for value in seq]
  File "C:\Python27\lib\site-packages\openpyxl\descriptors\base.py", line 59, in _convert
  raise TypeError('expected ' + str(expected_type))
  TypeError: expected &lt;class 'openpyxl.styles.fonts.Font'&gt;
  </code></pre>
  
  <p>If i try to print the existing workbook font, i get this, so it's reading properly</p>
  
  <pre><code>print wr_ac_sheet['A1'].font
  
  &lt;openpyxl.styles.fonts.Font object&gt;
  Parameters:
  name='Calibri', charset=None, family=2.0, b=False, i=False, strike=None, 
  outline=None, shadow=None, condense=None, color= 
  &lt;openpyxl.styles.colors.Color 
   object&gt;
  Parameters:
  tint=0.0, auto=None, theme=1L, rgb=None, indexed=None, type='theme', 
  extend=None, sz=11.0, u=None, vertAlign=None, scheme='minor'
  </code></pre>
  
  <p>i would like to assign all the properties of the cell (similar to format painter) to the new workbook, any guidance on how to do that?</p>