code: def should_bypass_proxies(url, no_proxy):
      
      # Prioritize lowercase environment variables over uppercase
      # to keep a consistent behaviour with other http projects (curl, wget).
      get_proxy = lambda k: os.environ.get(k) or os.environ.get(k.upper())
  
      # First check whether no_proxy is defined. If it is, check that the URL
      # we're getting isn't in the no_proxy list.
      no_proxy_arg = no_proxy
      if no_proxy is None:
          no_proxy = get_proxy('no_proxy')
      parsed = urlparse(url)
  
      if parsed.hostname is None:
          # URLs don't always have hostnames, e.g. file:/// urls.
          return True
  
      if no_proxy:
          # We need to check whether we match here. We need to see if we match
          # the end of the hostname, both with and without the port.
          no_proxy = (
              host for host in no_proxy.replace(' ', '').split(',') if host
          )
  
          if is_ipv4_address(parsed.hostname):
              for proxy_ip in no_proxy:
                  if is_valid_cidr(proxy_ip):
                      if address_in_network(parsed.hostname, proxy_ip):
                          return True
                  elif parsed.hostname == proxy_ip:
                      # If no_proxy ip was defined in plain IP notation instead of cidr notation &
                      # matches the IP of the index
                      return True
          else:
              host_with_port = parsed.hostname
              if parsed.port:
                  host_with_port += ':{}'.format(parsed.port)
  
              for host in no_proxy:
                  if parsed.hostname.endswith(host) or host_with_port.endswith(host):
                      # The URL does match something in no_proxy, so we don't want
                      # to apply the proxies on this URL.
                      return True
  
      with set_environ('no_proxy', no_proxy_arg):
          # parsed.hostname can be `None` in cases such as a file URI.
          try:
              bypass = proxy_bypass(parsed.hostname)
          except (TypeError, socket.gaierror):
              bypass = False
  
      if bypass:
          return True
  
      return False
docs: Returns whether we should bypass proxies or not.
  
      :rtype: bool