def fibs(n, m):
    """
    Yields Fibonacci numbers starting from ``n`` and ending at ``m``.
    """
    a = b = 1
    for x in range(3, m + 1):
        a, b = b, a + b
        if x >= n:
            yield b
def fibs ( n , m ) : a = b = 1 for x in range ( 3 , m + 1 ) : a , b = b , a + b if x >= n : yield b
Yields Fibonacci numbers starting from ``n`` and ending at ``m``.