如何将数学运算应用于python中列表中的每个数字？

Question

我是python的初学者(一周).在这里,我尝试打印60的所有素因子的列表.但对于第19行,我收到以下错误: TypeError:%支持的操作数类型:'float'和'list'

代码:

whylist = []
factor = []
boom = []
primefactor = []
n = 60
j = (list(range(1, n, 1)))



for numbers in j:
    if n%numbers == 0:
        whylist.append(numbers)
        for everynumber in whylist:
            factor.append(everynumber)

for things in factor:
    u = (list(range(1, things, 1)))
    d = float(things)
    if d%u == 0:
        boom.append(things)
    if len(boom) == 1:
        for every in boom:
            primefactor.append(every)
print(primefactor)

我究竟做错了什么？

Answer 1

要将数学运算应用于列表中的每个元素,可以使用列表推导:

new_list = [ x%num for x in old_list]

还有其他方法可以做到这一点.有时人们会使用map

new_list = map(lambda x: x%num, old_list)

但大多数人更喜欢第一种形式,它通常比使用更有效和清晰lambda(当你刚开始学习python时可能有点混乱).

编辑

这是你正在尝试的递归实现:

def factorize(n):
    out=[]
    for i in range(2,n):
        if(n%i == 0): #first thing to hit this is always prime
            out.append(i) #add it to the list
            out+=factorize(n/i)  #get the list of primes from the other factor and append to this list.
            return out
        else:
            return [n] # n%i was never 0, must be prime.

print factorize(2000)