>>> x = '12345'
>>> list(x)
['1', '2', '3', '4', '5']

>>> map(lambda i:int(i),list(x))
[1, 2, 3, 4, 5]

a = map(int, raw_input("enter 4-digit number "))
print ('neravno', 'ravno')[sum(a[:2])==sum(a[2:])]

a_string = raw_input("enter 4-digit number ")
a = map(int, a_string)  # или a=[int(x) for x in a_string]
if a[0]+a[1]==a[2]+a[3]:
	print 'ravno'
else:
	print 'neravno'