Yandex.Money account ID verification in Python

yandex_money.py

# coding=utf-8

# Author: Yaroslav Stavnichiy

def verify_account_id(acct):
  if not isinstance(acct, (str, unicode)):
    return False
  try:
    E=[int(c) for c in acct]
  except:
    return False

  N=E[0]
  if N==0: return False
  if len(E)<N+4: return False
  X=E[1:N+1]
  Y=E[N+1:-2]
  Z=E[-2]*10+E[-1]
  if len(Y)>20: return False
  if Z==0: return False
  return account_number_redundancy(X, Y)==Z

def account_number_redundancy(X, Y):
  T=Y[::-1] + [0]*(20-len(Y)) + X[::-1] + [0]*(10-len(X)) # [::-1] reverses the list
  Z=0
  A=70
  for TI in T:
    TI=10-(-TI%10)
    Z=(Z + TI*A % 99) % 99
    A=A*13 % 99
  return Z+1


if __name__=='__main__':
  # контрольные примеры счетов
  print verify_account_id('512345678925')
  print verify_account_id('498765432131')
  print verify_account_id('41001100113')
  print verify_account_id('41001123494')
  print verify_account_id('41002100117')
  print verify_account_id('41002123498')
  print verify_account_id('41003100121')
  print verify_account_id('41003123403')
  # негативный тест - ошибка в одной цифре счета
  print verify_account_id('41003103403')