Section 1.1: Common Mistake 1 - Overly Complex Functions

What’s wrong with this Python code snippet?

def validate(name, email):

if re.fullmatch(name_regex, name):

print("valid name")

else:

print("invalid name")

if re.fullmatch(email_regex, email):

print("valid email")

else:

print("invalid email")

Although we have imported the necessary regular expression module and defined all required variables, this function is too lengthy. Ideally, each function should focus on a single task. Our current function validates both the name and email, performing two separate actions.

To enhance readability, we could split this into two distinct functions:

def validate_email(email):

if re.fullmatch(email_regex, email):

print("valid email")

else:

print("invalid email")

def validate_name(name):

if re.fullmatch(name_regex, name):

print("valid name")

else:

print("invalid name")

Why is this important? Shorter functions are easier to understand, write, and test.

Section 1.2: Common Mistake 2 - Ambiguous Naming

Creative naming can sometimes backfire. Consider this pseudocode:

flavors = [vanilla, chocolate, raspberry]

victim = flavors.pop(1)

Or this less imaginative example:

array = [vanilla, chocolate, raspberry]

element = array.pop(1)

In both instances, the names chosen fail to enhance code quality and are generally poor programming practices. Names should be both descriptive and concise.

Section 1.3: Common Mistake 3 - Lack of Comments

Even if you can't be overly creative with variable names, don't leave your code silent. Comments are vital; they clarify what each part of your code does, aiding both others and your future self in understanding and modifying it without excessive effort.

Section 1.4: Common Mistake 4 - Repetition

Imagine writing a book that repeats the same chapter multiple times—your reader would be frustrated! The same principle applies to coding. Stick to the "Don't Repeat Yourself" (DRY) principle. If you find yourself copying and pasting code, it's a sign you should refactor that code into a function.

Section 1.5: Common Mistake 5 - Inconsistent Formatting

Consider this pseudocode:

if (time < 7 AM) {

snooze

}

else if (time >= 7 AM)

{

wake up

}

While different bracket placements may not affect the code's functionality, inconsistency can lead to confusion. Consistency in formatting is crucial in programming.

Section 1.6: Common Mistake 6 - Excessive Global Variables

Global variables, defined outside of functions, are accessible throughout the program. If they are not constant, they can be modified by different functions, potentially leading to program failures. Instead of the following:

flavors = [vanilla, chocolate, raspberry]

def replace_flavor():

flavors.pop()

flavors.append("pistachio")

Consider using local variables:

def replace_last_flavor():

flavors = [vanilla, chocolate, raspberry]

flavors.pop()

flavors.append("pistachio")