new devide

def devide(st, n):
    if n <= 0:
        return 'Error, n <= 0'
    else:
        L = i = 0 #L - for lines
        end = len(st)
        num = end/n+1 #print 'min lines = ' + str(num) + '\n'

        for L in range(2*num):
            i += n
            if i >= end:
                break
            while st[i] != (' ' or '.' or ',' or '?' or '!'):
                i -= 1
                if i < 1: #len one word > n
                    break
            if st[i] == (' ' or '.' or ',' or '?' or '!'):
                st = st[:i] + '\n' + st[i+1:]
        return st