How to solve this encoding error in Pandas

I'm having a problem when python reads xlsx with the pandas. When you run des_pt = (f_pt.head()[pt][0]).encode('utf-8').strip() and put the pt variable. It has an encode problem because some characters are in utf-8.

import pandas as pd

create_result = open('resultado.json', 'w')
i = 0

file_name_pt = pd.ExcelFile('pt.xlsx', encoding='utf-8')
file_name_en = pd.ExcelFile('en.xlsx')

f_pt = pd.read_excel(file_name_pt, sheet_name='Sheet1')
title_pt = f_pt.columns[1:]

f_en = pd.read_excel(file_name_en, sheet_name='Sheet1')
title_en = f_en.columns[1:]

create_result.write('{\n"resultados": [\n')
while i <= 25:
    for pt,en in zip(title_pt, title_en):
        print pt
        pt = pt.encode('utf-8').strip()
        en = en.encode('utf-8').strip()
        print pt

        des_pt = (f_pt.head()[pt][0]).encode('utf-8').strip()
        des_en = (f_en.head()[en][0]).encode('utf-8').strip()

        print des_pt     
        create_result.write('{\n"id":%s,\n"nome":"%s",\n"name":"%s",\n"descricao":"%s",\n"description":"%s",\n"combinacoes":[]},\n'%(i, pt, en, '', des_en))
        i+=1
create_result.write(']\n}')
create_result.close()
print 'Done'

The error message

Traceback (most recent call last):
  File "/Users/atila/Desktop/PyAutomate/firjan_result_generator/firjangenerator.py", line 23, in <module>
    des_pt = (f_pt.head()[pt][0]).encode('utf-8').strip()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/frame.py", line 2688, in __getitem__
    return self._getitem_column(key)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/frame.py", line 2695, in _getitem_column
    return self._get_item_cache(key)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/generic.py", line 2486, in _get_item_cache
    values = self._data.get(item)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/internals.py", line 4115, in get
    loc = self.items.get_loc(item)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/indexes/base.py", line 3066, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas/_libs/index.pyx", line 140, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/index.pyx", line 162, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/hashtable_class_helper.pxi", line 1492, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas/_libs/hashtable_class_helper.pxi", line 1500, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 'T\xc3\xa9cnico em Energias Renov\xc3\xa1veis'