string to int (complex)

oldstring = '134uu8'
print 'the initial string is: ', oldstring, '\n'
# int(oldstring)
# ValueError: invalid literal for int() with base 10: '134uu8'

newstring = [x for x in oldstring if x in "0123456789"]
print 'after list comprehension', newstring
newstring = "".join(newstring)
print 'after joining the list strings together', newstring, '\n'
now_an_int = int(newstring)
print 'applying int function to the purified string', now_an_int
print 'and its type is: ', type(now_an_int), '\n\n'