'str' does not support the buffer interface : I want to select those sentences which contains some conjunctions mentioned.But I am getting an error  as:Traceback (most recent call last):   File "positive_process3.py", line 14, in <module>     if word in text: TypeError: 'str' does not support the buffer interface.
My code is:
         
       import xlrd
       from xlrd import open_workbook
       import xlwt
       wb = open_workbook("C:/Users/SA769740/Desktop/result2/pos.xlsx")
       book = xlwt.Workbook(encoding="utf-8")
       sheet1 = book.add_sheet("Sheet 1")
       wordSet = [' for ', ' so ',' since ', ' Since ', ' because ', ' as ', ' As ', ' due to ', ' Due to ']
       count=1
       for sheet in wb.sheets():
    for row in range(sheet.nrows):
        text = ((sheet.cell(row,2).value).encode("utf-8"))
        l = ""
        for word in wordSet:
            if word in text:
                l += (word+" ")
        sheet1.write(row,0,sheet.cell(row, 0).value)
        sheet1.write(row,3, l)
        sheet1.write(row,4,count)
        sheet1.write(row,5,value)

        count += 1
        book.save('C:/Users/SA769740/Desktop/result2/pos_reviews_process3.xls')

   

I am using python 2.7.Error:line 14, in <module>    **if word in text**: TypeError: 'str' does not support the buffer interface