求斐波那契数列的两种思路

第一个思路是，求多少个斐波那契数：

def Fib(num):
    a, b = 0, 1
    res = []
    for i in range(num):
        res.append(a)
        a, b = b, a+b
    return res

Fib(10)
           

或者连列表也省了，直接打印：

def Fib(num):
    a, b = 0, 1
    for i in range(num):
        print(a, end=' ')
        a, b = b, a+b
Fib(10)
           

第二个思路是，求两个数之间的斐波那契数

def fib_between(start, end):
    a, b = 0, 1
    while a < end:
        if a >= start:
            print(a, end=' ')
        a, b = b, a + b
fib_between(1, 100)
           

把函数封装到类里，从第一个思路里变化出的

class Fib(object):
    def __init__(self, num):
        self.res = []
        self.num = num
        a = 0
        b = 1
        for i in range(num):
            self.res.append(a)
            a, b = b, a + b
    def __str__(self):
        return str(self.res)
    def __len__(self):
        return self.num
    
f = Fib(10)
print(f)
print(len(f))
           

 或者：

class Fib(object):
    def __init__(self):
        self.res = []

    def __call__(self, num):
        a = 0
        b = 1
        for x in range(num):
            self.res.append(a)
            a, b = b, a + b
        return self.res

f = Fib()
print(f(10))