Python 在过程中返回 None

我编写了一个程序来从字符串中提取链接。

请检查下面的代码。

def next_target(page):
    if (page.find('<a href') == -1):
        return 0,0
    link = (page.find('<a href='))
    first_quote = (page.find('"', link))
    second_quote = (page.find('"', first_quote + 1))
    url = page[first_quote + 1 : second_quote]
    return url, second_quote

def get_all_links(page):
    while True:
        url, endpos = next_target(page)
        if (url):
            print (url)
            page = page[endpos :]
        else:
            break

print (get_all_links('<div class="no-padding locale-column col-md-3"><a href="https://ee.000webhost.com/" class=""><span class="flag flag-ee"></span><span class="region">Eesti</span> <span class="language">Eesti</span></a><a href="https://es.000webhost.com/" class=""><span class="flag flag-es"></span><span class="region">España</span> <span class="language">Español</span></a><a href="https://fi.000webhost.com/" class=""><span class="flag flag-fi"></span><span class="region">Suomi</span> <span class="language">Suomi</span></a><a href="https://fr.000webhost.com/" class=""><span class="flag flag-fr"></span><span class="region">France</span> <span class="language">Français</span></a><a href="https://gr.000webhost.com/" class=""><span class="flag flag-gr"></span><span class="region">Ελλάδα</span> <span class="language">Ελληνικά</span></a><a href="https://hr.000webhost.com/" class=""><span class="flag flag-hr"></span><span class="region">Hrvatska</span> <span class="language">Hrvatski</span></a><a href="https://hu.000webhost.com/" class=""><span class="flag flag-hu"></span><span class="region">Magyarország</span> <span class="language">Magyar</span></a><a href="https://in.000webhost.com/" class=""><span class="flag flag-en-in"></span><span class="region">India</span> <span class="language">English</span></a><a href="https://th.000webhost.com/" class=""><span class="flag flag-th"></span><span class="region">ประเทศไทย</span> <span class="language">ไทย</span></a></div>'))

该程序正在提取所有链接。但与链接一起，None还会返回一个值。None提取链接后如何停止出现？

我编写了另一个程序来做完全相同的事情。但是，它也会返回一个None值。

请检查以下代码：

def page_pro(page):
    end_quote = 0
    if (page.find('<a href') == -1):
        return None
    else:
        while (page.find('<a href', end_quote) != -1):
            start_link = (page.find('<a href=', end_quote))
            first_quote = (page.find('"', start_link))
            end_quote = (page.find('"', first_quote + 1))
            url = page[first_quote + 1 : end_quote]
            print (url)

print (page_pro('<div class="no-padding locale-column col-md-3"><a href="https://ee.000webhost.com/" class=""><span class="flag flag-ee"></span><span class="region">Eesti</span> <span class="language">Eesti</span></a><a href="https://es.000webhost.com/" class=""><span class="flag flag-es"></span><span class="region">España</span> <span class="language">Español</span></a><a href="https://fi.000webhost.com/" class=""><span class="flag flag-fi"></span><span class="region">Suomi</span> <span class="language">Suomi</span></a><a href="https://fr.000webhost.com/" class=""><span class="flag flag-fr"></span><span class="region">France</span> <span class="language">Français</span></a><a href="https://gr.000webhost.com/" class=""><span class="flag flag-gr"></span><span class="region">Ελλάδα</span> <span class="language">Ελληνικά</span></a><a href="https://hr.000webhost.com/" class=""><span class="flag flag-hr"></span><span class="region">Hrvatska</span> <span class="language">Hrvatski</span></a><a href="https://hu.000webhost.com/" class=""><span class="flag flag-hu"></span><span class="region">Magyarország</span> <span class="language">Magyar</span></a><a href="https://in.000webhost.com/" class=""><span class="flag flag-en-in"></span><span class="region">India</span> <span class="language">English</span></a><a href="https://th.000webhost.com/" class=""><span class="flag flag-th"></span><span class="region">ประเทศไทย</span> <span class="language">ไทย</span></a></div>'))