import re
import csv
i_file = open('testcsv.csv','rt')
txt = ''
for row in i_file:
     txt += row #собираю файл в строку
txt = re.sub(r'[А-я]+', '1', txt) #шаблон чисто для проверки
print((txt))

i_file = open('testcsv.csv','rt',encoding="utf-8")

import csv

C:\Python27\python.exe C:/Users/User/PycharmProjects/csveditor/csveditor.py
Traceback (most recent call last):
  File "C:/Users/User/PycharmProjects/csveditor/csveditor.py", line 4, in <module>
    i_file = codecs.open('testcsv.csv','rt', encoding="utf-8")
  File "C:\Python27\lib\codecs.py", line 896, in open
    file = __builtin__.open(filename, mode, buffering)
ValueError: Invalid mode ('rtb')
Process finished with exit code 1

import re
import codecs
i_file = codecs.open('testcsv.csv','rt', encoding="utf-8")
txt = ''
for row in i_file:
     txt += row
txt = re.sub(r'[А-я]+', '1', txt)
print(txt)

import csv
res_list = []
with open('testcsv.csv', 'rt') as i_file:
    txt = csv.reader(i_file)
    for i in txt:
        data = str(i[0].decode("cp1251").encode("utf8")).replace(';', '')
        if data:
            res_list.append(data)
print ','.join(res_list)

print res_list[10]

for i in res_list:
    print i