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Otu Michael
Otu Michael

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So The Newbie Created a Utility File? (The Helper File)

As a newbie, don't take "these" software engineering practices as a trophy. You hear things like, "the code smells", "DRY", "KISS" and others. Seriously, don't. I mean, you could after you are done with your project and everything is working and you are happy. If you are happy, don't even touch the code. You are a newbie and we newbies love things when they are working. (Isn't that right?)

Reading about software engineering practices and what have you, as a newbie, can be very influential sometimes. A three hours practice project can become a week old if you are "lucky" - that is, you had another eye to tell you what went wrong. You could even hide your project in the 🗑️. (I meant you delete it because you don't want to be known as the guy with the most uncompleted projects)

Earlier on, I learnt you should not mix your helping functions with the "business logic". You have to separate them. This is called, separation of concerns. Ok!

He was like, "Hey bro! That is not a very good practice. Create a new file for your utility functions". So I created a file, called it utils.py and went for a water break. (I went to sleep, I was a newbie, what did you expect? Did I regret snoozing? Nah! I enjoyed it.).

The lesson here, read more about the concept and see how it should and could be used in your project. By this, how do you understand and interpret the concept? How does the concept fit into your current project?

The Sign-Up and Login Form

What makes one newbie more suitable for an entry-level job than another is the tendency to explore - experiment, break and fix.

This is was a practice project that swell up to become a full-blown project. I was just creating a sign up and login functionality and it became a whole project. Do you remember or know anything about cs50-flask by David Malan, Harvard? This link was not the one I watched, but it was cs50-harvard.

The Helper File

This file contains a whole lot of functionalities.

Generate Random Characters

There is a function for generating tokens for email and password updating.

from string import ascii_letters, digits
from random import randint

def generate_token():
    TOKEN_LENGTH = 6
    token = ""

    code_alphabet = ascii_letters + digits + "_"

    max = len(code_alphabet)

    for i in range(TOKEN_LENGTH):
        token += code_alphabet[randint(0, max - 1)]

    return token
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How is this function working?

  • ascii_letters returns abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.
  • digits returns 0123456789.
  • randint is a function that takes a min and max inclusive argument.
  • This function, generate_token, takes no argument.
  • TOKEN_LENGTH is the number of characters I want to generate. In this case, it is 6.
  • token is an initialized string variable to hold the random characters to be generated.
  • code_alphabet is a string concatenation of ascii_letters, digits and an _.
  • max is assigned the length of code_alphabet. max was a very bad name. Do you know why as a newbie?
  • using the for-range looping construct, looping TOKEN_SIZE times, indexing code_alphabet using the randint function passing 0 and max - 1 as arguments. We want to be able to index the first element from code_alphabet so we passed 0 and max - 1 so that the value would be in the range of index else we'd get an IndexError.
  • The random character from code_alphabet[randint(0, max - 1)] is add to token
  • token is returned as a result

What will I change if I were to rewrite generate_token today?

  • To make use of the generate_token function somewhere, I'd rather pass the desired token size to it. I'd make it by default, 6 characters. So the function definition would look like, def generate_token(token_size=6): ...
  • I will rename code_alphabet to token_source
  • I will rename max to token_source_length or token_source_size. If were look at token += code_alphabet[randint(0, max - 1)], we would realize that, max - 1 was used as the endpoint for the randint function. So we can rather name it end_point. So I will let end_point = len(token_source) - 1
  • Assign start_point the value, 0. Pass start_point as the first argument in the randint function.
  • I will use "string" comprehension and the string join method to create the token. I usually don't favour this syntax if it makes reading the code a headache.
  • Instead of assigning the generated token to token and then returning token after the loop, I will just return the generated token. This way I won't have to initialize token.
  • A linter will warn you that there is an unused variable if the variable was declared or initialized but was never used. So instead of using a variable in the for-range construct, I'd use _ - a throw-away-variable.

The rewritten function will look like the snippet below.

from string import ascii_letters, digits
from random import randint

def generate_token(token_size=6):
    token_source = ascii_letters + digits + "_"

    start_point = 0
    end_point = len(token_source) - 1

    return "".join(
        token_source[randint(start_point, end_point)]
            for _ in range(token_size)
    )
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Lesson

Do you remember, "with power comes great responsibilities"? Some say the inverse. Well, with experience comes a different code. This does not mean there won't be flaws. A flaw may not necessarily be a bug or error. A design approach could be a flaw. The readability issue could be a flaw. Complexity could be a flaw.

What changes would you make in the snippet above?

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