Question

我编写了以下用于查找N素数的代码。但是，我无法将其存储在列表中。

     def prime(n):

        global count
        s=0
        flag=0
        ls=[]
        for i in range(2,n/2+1):
                     if(n%i==0):
                           flag=1
                           break

        if(flag==0):
                print n
                ls.append(n)
                count=count+1
        print ls

    # main pro
    n=input("Enter the number of prime numbers to be displayed: ")
    print"The prime numbers are:"  
    count=0
    x=2
    while(count<n):
             prime(x)
             x+=1

我想要的输出应该是：

    Enter the number of prime numbers to be displayed: 5
    [2, 3, 5, 7, 11]

但是当我运行程序时，输出为：

    Enter the number of prime numbers to be displayed: 5
    The prime numbers are:
    2
    [2]
    3
    [3]
    []
    5
    [5]
    []
    7
    [7]
    []
    []
    []
    11
    [11]

如何在不更改上述代码的情况下将素数添加到列表中？我应该在以后的部分附加元素吗？我是Python新手，所以非常感谢所有帮助！谢谢！

Answer 1

这将返回count素数组：

def get_primes(count):
    primes = []

    n = 2
    while len(primes) != count:
        for i in range(2, n // 2 + 1):
            if n % i == 0:
                break
        else:
            primes.append(n)
        n += 1

    return primes

你可以像这样使用它：

n=input("Enter the number of prime numbers to be displayed: ")
array_of_n_prime_numbers = get_primes(n)
print("The prime numbers are:", array_of_n_prime_numbers)

Answer 2

试试这个

def prime(x):
    if x<1:
        return []
    prime_numbers = [2,3]
    if x<3:
        return prime_number[:x]
    for i in range(2,x):
        next_pn = prime_numbers[-1]+2
        while any(not(next_pn%pn) for pn in prime_numbers):
            next_pn += 2
        prime_numbers.append(next_pn)
    return prime_numbers

N = input("Enter the number of prime numbers to be displayed:")
print (prime(int(N)))

输出

Enter the number of prime numbers to be displayed:5
[2, 3, 5, 7, 11]

不需要遍历所有数字，而是可以在它之前只遍历素数。

Answer 3

这是一个简单的方法：

def prime(n):
    ls = [2,3]
    if (n < 3):
        return ls[:n]
    for i in range(2,n):
        generate = ls[-1]+2
        while any(not(generate%num) for num in ls):
            generate += 2
        ls.append(generate)
    return ls



n = int(input("Enter the number of prime numbers to be displayed:"))
print (prime(n))

输入为5时输出

：

[2, 3, 5, 7, 11]

Python程序在列表中存储前N个素数？

3 个答案: