Write a function that when given a URL as a string, parses out just the domain name and returns it as a string. For example:
```python
domain_name("http://github.com/carbonfive/raygun") == "github" 
domain_name("http://www.zombie-bites.com") == "zombie-bites"
domain_name("https://www.cnet.com") == "cnet"
```

Difficulty: introductory

Starter code:

def domain_name(url):
	

Solutions:
def domain_name(url):
    return url.split("//")[-1].split("www.")[-1].split(".")[0]

import re
def domain_name(url):
    return re.search('(https?://)?(www\d?\.)?(?P<name>[\w-]+)\.', url).group('name')


def domain_name(url):
    url = url.replace('www.','')
    url = url.replace('https://','')
    url = url.replace('http://','')
    
    return url[0:url.find('.')]

def domain_name(url):
    a=url.replace('http:',' ').replace('https:',' ').replace('/',' ').replace('//',' ').replace('.',' ').replace('www',' ').split()
    return(a[0])

def domain_name(url):
    print(url)
    url = url.replace("http://","")
    url = url.replace("https://","")
    url = url.replace("www.","")
    end = url.find(".")
    return url[0:end]

def domain_name(url):
    if 'www.' in url:
        x = url.split('www.')
        url = x[1]
    if '://' in url:
        x = url.split('://')
        url = x[1]
    if '.' in url:
        x = url.split('.')
        x = x[0]
    return x

import re

def domain_name(url):

    return re.search("(https?:\/\/)?(www\d?\.)?([\w-]+)\.",url).group(3)
    


def domain_name(url):
    url=url.replace("http://www.","")
    url=url.replace("www.","")
    url=url.replace("https://","")
    url=url.replace("http://","")
    return url[:url.index(".")]

import re
def domain_name(url):
    return re.search(r'(/{2})?(www\.)?(?P<name>[\w-]+)[.?]',url).group('name')

from urllib.parse import urlparse

def domain_name(url):
    parsed = urlparse(url)
    dom = parsed.netloc
    path = parsed.path
    if dom:
        dom_spl = dom.split('.')
        if dom_spl[0] == 'www':
            return dom_spl[1]
        return dom_spl[0]
        
    elif path:
        path_spl = path.split('.')
        if path_spl[0] == 'www':
            return path_spl[1]
        return path_spl[0]


from re import compile, match

REGEX = compile(r'(http[s]*://)?(www.)?(?P<domain>[\w-]+)\.')


def domain_name(url):
    return match(REGEX, url).group('domain')


def domain_name(url):
    if '//' in url:
        list1 = url.split('//')
    if 'www.' in url:
        list1 = url.split('www.')
    try:
        str1 = list1[1]

        list2 = str1.split('.')
        return(list2[0])
    except:
        list2 = url.split('.')
        return(list2[0])


import re
def domain_name(url):
    # checking for URL keyword
    if "www" in url:
        url = url.replace("www."  , "")
    regex1 = "\/\/[^.]+"
    regex2 = "[^.]+"
    if url.startswith("http"):
        domain = re.findall(regex1 , url)
    else:
        domain = re.findall(regex2 , url)


    if "//" in domain[0]:
        return domain[0][2:]
    else:
        return domain[0]

import re

def domain_name(url):
      return re.search(r'(?:https?://)?(?:w{3}\.)?(.*?)\..*', url).group(1)


domain_name=lambda url:url.replace("http://","").replace("www.","").replace("https://","").replace("."," ").split()[0]

import re


def domain_name(url):
    if url.find("://") == -1:
        url += "://" + url;
    return re.findall(".*\://(?:www.)?([^\/]+)", url)[0].partition(".")[0];


import re
def domain_name(url):
    print(url)
    ur=r'(?:https?://www\.|www\.|https://www\.|https?://|)(.+?)\.'
    a=re.findall(ur, url)
    if len(a)==0:return ""
    return a[0]

def domain_name(url):
    domain = url.replace('http://', '').replace('www.', '').replace('https://', '')
    domain1 = domain.split('.')
    return ''.join(domain1[0])
    


import re


def domain_name(url):
    match = re.search(r'(https?://)?(www\d?\.)?(?P<name>[\w-]+)\.',url)
    return match.group('name')

import re
def domain_name(url):
   return re.sub(r'(http(s)?:\/\/)?(www\.)?',"",url).split(".")[0]

import re
def domain_name(url):
    return re.match("(?:https?\://)?(?:www.)?([a-z0-9-]*)\.*",url).group(1)

import re

def domain_name(url):
    url_pattern = re.compile(r'^(https?://(www.)?|(www.))?([^.]+)\..*$')
    return url_pattern.sub(r'\4', url)

import re

def domain_name(url):
    pattern = r'^(https?://(www.)?|(www.))?([^.]+)\..*$'
    return re.sub(pattern, r'\4', url)

import re

def domain_name(url):
    r = re.sub(r'www\.', '', url)
    r = re.search(r'[\w\-]{3,}\.\w{2,3}', r)
    r = re.search(r'[\w\-]+', r[0])
    return r[0]

import re

def domain_name(url):
    domain = re.sub('(http[s]?://)?(www\.)?([^\.]+)(.*)', '\g<3>', url)
    return domain

import re
def domain_name(url):
    return re.findall('(?:http[s]?://)?(?:www\.)?([0-9a-zA-Z\-]+)\..*', url)[0]

def domain_name(url):
    if 'www.' in url:
        url = url.split('www.')[-1]
    elif '//' in url:
        url = url.split('//')[-1]
    return url.split('.')[0] 

from urllib.parse import urlparse

def domain_name(url):
    if not (url.startswith("https://") or url.startswith("http://")):
        url = "http://" + url
    return urlparse(url).hostname.replace("www.", "").split(".")[0]

import re

def domain_name(url):
    pattern = "[\-\.a-z0-9]+|www.[\-a-z0-9]+\."
    string = re.findall(pattern, url)
    string = string[1 if len(string) > 1 and 'http' in string[0] else 0]
  
    return re.sub("www\.|\/\/|\.[\.a-z]+$|\.", "", string)


from re import sub

def domain_name(url):
    return sub(r'^(?:https?:\/\/)?(?:www\.)?([\w\-]+)\.(?:.*?)$', r'\1', url)

def domain_name(url):
    d = url.split('//')
    try:
        f = d[1].split('.')
    except IndexError:
        f = d[0].split('.')

    return f[0] if f[0] != 'www' else f[1]

def domain_name(url):
    napis = url
    
    if "//" in napis:
        tab = napis.split("//")
        czlon = tab[1]
        print(czlon[0])
    else:
        czlon = napis
    
    if not czlon.startswith("www"):
        zmienna = czlon.split(".")
        print(zmienna[0])
        wynik = zmienna[0]
    else:
        zmienna = czlon.split(".")
        print(zmienna[1])
        wynik = zmienna[1]
    return wynik

def domain_name(url):
    filter_list = ['http://', 'www.', 'https://']
    for f in filter_list:
        if f in url:
            url = url.replace(f, '')
    new_url = url.split(".")
    return new_url[0]

def domain_name(url):
    print(url)
    if "//" in url:
        url = url.split("//", 1)[1]
    if "www." in url:
        url = url.split("www.", 1)[1]
    return url.split(".", 1)[0]

def domain_name(url):
     return url.replace("www.", "").replace("http:", "").replace("https:", "").replace("/", "").split(".")[0]

def domain_name(url):
    url = url.replace("http://www.", "")
    url = url.replace("https://", "")
    url = url.replace("http://", "")
    url = url.replace("www.", "")
    a = ""
    for i in url:
        if i != ".":
            a = a + i
        else:
            return a

def domain_name(url):
    if "w" * 3 in url:
        new_url = url[(url.index(".") + 1):]
        return new_url[: new_url.index(".")]

    elif "/" * 2 in url:
        return url[(url.index("/") + 2):url.index(".")]

    else:
        return url[:url.index(".")]

def domain_name(url):
    if url.startswith('http'): url=url.split('//')[1]
    if url.startswith('www'): return(url.split('.')[1])
    return(url.split('.')[0])    

def domain_name(url):
    url=url.split('www.')[-1]
    url=url.split('//')[-1]
    url=url.split('.')[0]
    
    return url

import re

def domain_name(url):
    return re.sub(r'/[a-z]*/?','',re.sub(r'\.[a-z]*','', re.sub(r'(https?|www)(://|\.)','',url)))

def domain_name(url):
    
    url = url.replace('www.', '').replace('https://', '').replace('http://', '')
    
    
    index = url.find('.')
    return url[0:index]
    pass

def domain_name(url):
    url = url.replace('http://', '')
    url = url.replace('https://', '')
    url = url.replace('www.', '')
    url = url.split('.')
    return url[0]

def domain_name(url):
    return url.split('//')[-1].replace('www.', '').split('.')[0]

def domain_name(url):
    return url.replace("https://", "").replace("http://", "").replace("www.", "").split(".")[0]

def domain_name(url):
    if url[0:8] == "https://" or url[0:7] == "http://":
        if url[8:12] == "www." or url[7:11] == "www.":
            return url.partition('.')[2].partition('.')[0]
        else:
            return (url.partition('//')[2]).partition('.')[0]
    else:
        if url[0:4] == "www.":
            return url.partition('.')[2].partition('.')[0]
        else:
            return url.partition('.')[0]


import re
def domain_name(url):
    url = re.sub(r'(https:\/\/www\.|http:\/\/www\.|https:\/\/|http:\/\/|www\.)','',url)
    return re.sub(r'\..+', '', url)

def domain_name(url):
    if "www." in url:
        startpos = url.find("www.") + 4
    elif "://" in url:
        startpos = url.find("://") + 3
    else:
        startpos = 0
    endpos = url.find(".", startpos)
    return(url[startpos:endpos])

from urllib.parse import urlparse

def domain_name(url):
    url = url.replace("www.","")
    url = url.replace("http://","")
    url = url.replace("https://","")
    domain_name = url.split('.')[0]
    return(domain_name)
            
            


def domain_name(url):
    url = url.replace("www.","").split("/")
    for i in url:
        if '.' in i:
            url = i
            break
    domain,mid,tail = url.partition(".")
    return domain

def domain_name(url):
    url = url.replace("http://", '')
    url = url.replace("https://", '')
    url = url.replace("www.", '')
    last = url.rfind('/')
    
    if last is not None:
        url = url[:last]
        
    dot = url.find('.')
    
    if dot is not None:
        url = url[:dot]
        
    return url

def domain_name(url):
    if url.startswith('htt'):
        removehttp = url.split('//')
        if removehttp[1].startswith('w'):
            removewww = removehttp[1].split('www.')
            solution = removewww[1].split('.')
            return solution[0]
        else:
            solution = removehttp[1].split('.')
            return solution[0]
    elif url.startswith('w'):
        removewww = url.split('www.')
        solution = removewww[1].split('.')
        return solution[0]
    else:
        solution = url.split('.')
        return solution[0]

def domain_name(url):
    print(url)
    start=url[0:3]
    print(start)
    http="htt"
    www='www'
    start2=url[0:10]
    http2='http://www'
    if start==http and start2!=http2:
        split_list=url.split('//')
        return split_list[1].split('.')[0]
    elif start==www:
        return url.split('.')[1]
    elif start2==http2:
        return url.split('.')[1]
    else:
        return url.split('.')[0]


def domain_name(url):
    for i in ["https://","http://","www.",".com",".in"]:url=url.replace(i,'')
    return url.replace('.','/').split('/')[0]

def domain_name(url):
    for i in ['http://','https://','.com','www.']:url=url.replace(i,'')
    return url.replace('.','/').split('/')[0]


import regex as re

def domain_name(url):
    return re.sub('(https?:\/\/|www\.)*([^.]*)\..*', r'\2', url)

import re
def domain_name(url):
    url = url.replace("https://", "").replace("http://", "").replace("www.", "")
    print((re.findall("^[^\.]+",url)))
    return (re.findall("^[^\.]+",url))[0]


import re

def domain_name(url):
    pat = r'(http[s]?://)*(www\.)*(\w+[-_]*\w+)\b(\..*)'
    res = re.match(pat, url)
    return str(res.group(3))

def domain_name(url):
    print(url)
    split = url.split(".")
    if (split[0] == "www"):
        return split[1]
    elif("http://www" in split[0] or "https://www" in split[0]):
        return split[1]
    elif("http" in split[0] or "https" in split[0]):
        split = split[0].split("//")
        return split[1]
    else:
        return split[0]


def domain_name(url):
    if url[:4] == 'http' or url[:4] == 'www.':
        url = url[4:]
        if url[0] == 's':
            url = url[1:]
    if url[:3] == '://':
        url = url[3:]
    if url[:4] == 'www.':
        url = url[4:]
    dot = url.index('.')
    url = url[:dot]
    return url


import re
def domain_name(url):
    return [m for m in re.findall('[(\w+)(?=\-)]+(?=\.)', url) if m != 'www'][0]

def domain_name(url):
    parts = url.split("//")
    portion = parts[0]
    if len(parts) > 1:
        portion = parts[1]
    
    if "www" in portion:
        return portion.split(".")[1]
    return portion.split(".")[0]

import re

def domain_name(url):
    if 'www.' not in url:
        if '://' in url:
            m = re.search('(?<=//)\S+?(?=\.)', url)
        else:
            m = re.search('\S+?(?=\.)', url)
    else:
        m = re.search('(?<=\.)\S+?(?=\.)', url)

    return m.group(0)

def domain_name(url):
    return url.split('//')[-1].split('.')[1] if 'www' in url else url.split('//')[-1].split('.')[0]

def domain_name(url):
    if 'www.' in url:
        return url.split('.')[1].split('.')[0]
    elif '.' and '//' in url:
        return url.split('//')[1].split('.')[0]
    else:
        return url.split('.')[0]

def domain_name(url):
    if url[0:4] == 'http':
        url = url[url.find('//')+2:-1]
    url = url.split('.')
    return url[0] if url[0] != 'www' else url[1]

import re
# Use regex to grab domain name
regex_pattern = "(https?:\/\/)?[w]{0,3}\.?([A-Z,a-z,0-9,-]*).*"

def domain_name(url):
    print(url)
    return re.search(regex_pattern, url).group(2)

import re

domain_name = lambda url: re.search(r"^(https?\:\/\/)?(www.)?([a-zA-Z0-9\-]+)", url).group(3)

def domain_name(url):
    print(url)
    # finds start of url
    if "www." in url:
        s = url.find("www.") + 4
    elif "//" in url:
        s = url.find("//") + 2
    else:
        s = 0
    
    # finds end of url
    e = url.find(".", s)
    
    return url[s:e]


import re
def domain_name(url):    
    g = re.sub('((http|https)\:\/\/)?(www.)?', '',url)
    s = re.search('[a-zA-Z0-9-]*.', g)
    
    return s.group()[:-1]

import re

def domain_name(url):
    return re.compile('(https:|http:)?(//)?(www.)?([\w+-]+)').match(url).group(4)

def domain_name(url):
    import re
    result = re.sub('^.*//|www\.', '', url) # del 'http://' and 'www.' (start of url)
    result = re.sub('\..*', '', result)     # del .com, .co.jp, ... (end of url)
    return result

def domain_name(url):
    domain = ''
    adding = False
    if 'www' in url:
        for char in url:
            if char == '.':
                adding = not adding
                if not adding: break
            if adding:
                domain += char
    elif url[6] == '/':
        for char in url:
            if char == '/':
                adding = True
            elif char == '.':
                adding = False
                break
            if adding:
                domain += char
    else:
        adding = True
        for char in url:
            if char == '.':
                adding = False
                break
            if adding:
                domain += char
            
    domain_arr = list(domain)
    if '/' in domain_arr: domain_arr.remove('/')
    if '/' in domain_arr: domain_arr.remove('/')
    if '.' in domain_arr: domain_arr.remove('.')
    print(url)
    return ''.join(domain_arr)

def domain_name(url):
    print(url)
    first=""
    second= ""

    if "www" in url:

        first = url.split("www.")[1]
        second = first.split(".")[0]

    elif "http" in url:
        first = url.split("://")[1]

        second = first.split(".")[0]
        
    else:
        second = url.split(".")[0]




    return second

def domain_name(url):
    domain = ""
    if url.startswith("http"):
        url = url[url.find("//")+2:]
    if url.startswith("www."):
        domain = url[4:][:url[4:].find(".")] 
    else:
        domain = url[:url.find(".")]
    return domain


def domain_name(url):
    import re
    return re.search('(https://)?(www\d?\.)?(?P<domain>[\w-]+)\.', url).group('domain')