Web爬虫的问题，不知道如何解决这个问题

我正在创建一个网络爬虫，我遇到了一个问题 . 我的脚本所做的是抓取链接的第一页，然后抓取它找到的页面上的链接 . 我似乎遇到的问题是在第一组链接被抓取后，它会从第一次抓取中抓取网页的链接，但是似乎有一个问题链接正在使用TLD（http://example.com vs / about for例） . 我已经尝试分解这些链接并添加一些过滤来捕获和记录它们，我已经尝试运行我自己的命令来过滤掉完整的URL，似乎没有任何区别 . 任何帮助，将不胜感激 . 以下是代码：

import sys
import requests
from bs4 import BeautifulSoup

# creating requests from user input
url = raw_input("Put in your domain! Without the 'http://www' part : ")

def makeRequest(url):
    print("Trying...", url)
    r = requests.get('http://' + url)
    # Adding in BS4 for finding a tags in HTML
    soup =  BeautifulSoup(r.content, 'html.parser') 
    # Writes a as the link found in the href
    output = soup.find_all('a')
    return output

def makeFilter(link):
    # Creating array for our links
    found_link = []
    for a in link:
        a = a.get('href')
        a_string = str(a)

        if not a_string:
            continue    
        # if statement to filter our links
        if a_string[0] == '/':
            # Realtive Links
            found_link.append(a_string)     

        if 'http://' + url in a_string:
            # Links from the same site
            found_link.append(a_string)

        if 'https://' + url in a_string:
            # Links from the same site with SSL
            found_link.append(a_string)

        if 'http://www.' + url in a_string:
            # Links from the same site
            found_link.append(a_string)

        if 'https://www.' + url in a_string:
            # Links from the same site with SSL
            found_link.append(a_string)

    output = found_link
    # print a_string

    return output   

# Function for removing duplicates
def remove_duplicates(values):
    output = []
    seen = set()
    for value in values:
        if value not in seen:
            output.append(value)
            seen.add(value)
    return output

# Makes the request -> Filters the links -> Removes duplicates
def createURLList(values):
    global filtered_list
    try:
        requests = makeRequest(values)
    except:
        print "Try again."
    try:
        new_list = makeFilter(requests)
    except:
        print "I can't make a list out of this."
    try:
        filtered_list = remove_duplicates(new_list)
    except:
        print "I can't do shit with this list."

    return filtered_list

result = createURLList(url)

# print result
crawled_urls = []
crawled_urls = open('crawled_urls.txt', 'w')

# for verifying and crawling resulting pages
for b in result:
    sub_directories = createURLList(url + b) # issue is right here, it's adding the url on the full URL in some instances

    # remove_duplicates(sub_directories)
    for z in sub_directories: # goes through the arrays crawled 
        crawler = []
        crawler.append(z)
        crawler = remove_duplicates(crawler) # remove duplicates from list
        crawler = str(crawler)
        crawled_urls.write(crawler + '\n')
crawled_urls.close()