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Structuring Your Code

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DRY

4:29 with Megan Amendola

Keep your code free from repeats.

DRY, or don’t repeat yourself, is another popular acronym reminding you to keep your code free of repeats whenever possible.

Refactoring is the process by which you improve existing code.

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    Repeating yourself is a common mistake new programmers make. 0:00
    It can be easy when creating a project 0:05
    to not notice you've created the same variable twice, or repeated some steps. 0:07
    Every coder creates repeat code at one time or another. 0:13
    DRY or don't repeat yourself is a great acronym to keep in mind as you 0:19
    code to help you remember to review your work and check for those repeats. 0:24
    The best way to see how DRY works is to see it in action. 0:30
    Let's tackle some repeats, open the DRY file and let's dive in. 0:34
    In this file are two lists with items inside. 0:39
    Below, I'm converting the price into numbers instead of strings for 0:43
    both fruits and vegetables. 0:48
    Lastly, I'm adding another key value pair to each. 0:50
    There's a lot of repeating going on here. 0:55
    One way to tackle this is to use for loops. 0:58
    Let's try it and see what our code looks like. 1:01
    For fruit in fruits, 1:09
    Tab this over and we can remove the number and the s. 1:15
    And delete the extras. 1:22
    For vegetable in vegetables, 1:28
    same thing, tab over, remove the index and 1:32
    the s and remove the excess. 1:39
    For fruit in fruits, 1:50
    Remove the index and s, remove the excess, 1:57
    And one more time for 2:03
    vegetable in vegetables, tab, 2:06
    index and s, remove the excess. 2:11
    Already a lot cleaner, right? 2:18
    Well, this is definitely better, our code here is still repeating the same tasks. 2:21
    We're repeating the tasks to translate the price string into a number and 2:27
    the task to add a location. 2:32
    Let's make these two tasks into functions. 2:34
    The first we can call convert_price. 2:38
    It will take the list we want to work with as a parameter, 2:48
    then we can use the same for loop, To convert the price. 2:52
    We just need to change out fruits to list and fruit to item. 3:02
    Item and item. 3:10
    Now all we need to do is get rid of the vegetable version, and 3:17
    call our function twice with our two lists. 3:22
    Let's do the same thing for our second function and call it add_location 3:38
    Now, we're not repeating for loops either. 4:13
    Most of the time when I see repeated code, 4:17
    it means I need to convert it into a function. 4:20
    You've tackled creating more dry code, awesome. 4:24

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