python - Why not use fewer lines of code in this function (urllib.urlopen)? -

i working through tutorial beginner's level python, , found can same result 1 less line of code, , don't know why instructor (he professional 15+ years) chose additional line/variable. assumption either has low-level use of urllib library, and/or may programming best-practices, i'm hoping might able tell me why.

the function in question is:

from urllib.request import urlopen  def load_page(url: str):     response = urlopen(url)     html = response.read().decode('utf')     return html 

as i've learned, returns actual html of request. while debugging , inspecting each piece of function does/returns, found can same result (the html of request) removing "response" variable completely:

def load_page(url: str):     html = urlopen(url).read().decode('utf')     return html 

is there reason want first assign urlopen(url) response, instead of running read() , decode() directly on urlopen(url)?

like functions should "do 1 thing" same said each line of code. there has been similar question (about broader concept of reducing line count on software engineering: "is fewer lines of code better?")

it's 1 operation make request, 1 operation contents of request.

from urllib.request import urlopen  def load_page(url: str):     response = urlopen(url)               # make request     html = response.read().decode('utf')  # contents     return html 

this has number of advantages:

• debugging: if fails know fails (in terms of line number). did fail when doing urlopen or when decode?
• extending code: want inspect status of response or header? easy, access response.status or response.headers.
• readability: more operations/calls there in 1 line harder understand line doing.

however in case "acceptable" read().decode(...) in return line:

from urllib.request import urlopen  def load_page(url: str):     response = urlopen(url)               # make request     return response.read().decode('utf')  # contents , return