prime numbers & Fibonacci series

[hug2wisdom]

for n in range(2, 10):
    for x in range(2, n):
        if n % x == 0:
            print(n, 'equals', x, '*', n // x)
            break
    else:
        print(n, 'is a prime number')

(Yes, this is the correct code. Look closely: the else clause belongs to thefor loop, not the ifstatement.)

else 不仅仅可以与 if 连在一起使用，还可以与 for，try，while 使用。

[hug2wisdom]

list(range(10, 10))， 返回的是 []

[hug2wisdom]

Fibonacci series

def fib(n): # write Fibonzcci series up to n
    """print a Fibonacci series up to n."""
    a, b = 0, 1
    while a < n:
        print(a, end = ' ')
        a, b = b, a + b
    print()
fib(2000)
# result
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597