python
# Implicit ❌
def area(l, w):
    return l * w

# Explicit ✅
def calculate_rectangle_area(length, width):
    return length * width

python
# Complex ❌
result = []
for i in range(10):
    if i % 2 == 0:
        result.append(i)

# Complex but organized ✅️
result = [i for i in range(10) if i % 2 == 0]

# Nested ❌
if x > 0:
    if y > 0:
        if z > 0:
            ...

# Flat ✅️
if x > 0 and y > 0 and z > 0:
    ...

# Dense ❌
if x > 0: print("Positive"); print("Check done")

# Sparse ✅️
if x > 0:
    print("Positive")
    print("Check done")

# Silent error ❌
try:
    result = some_function()
except:
    pass  # No error handling

# Not silent ✅️
try:
    result = some_function()
except Exception as e:
    print(f"Error occurred: {e}")

# Not explicit ❌
try:
    result = some_function()
except Exception:
    pass

# Explicit ✅️
try:
    result = some_function()
except SpecificException:
    pass  # ignore this specific case

# One way ✅️
list.append(item)

# Not obvious alternatives should be avoided

age = 33
formatted = f"Age: {age}"
formatted = "Age: {}".format(age)
formatted = "Age: %d" % age

assert_stmt ::=  "assert" condition ["," message]

assert 1 < 2 # nothing happens
assert 1 > 2 # AssertionError

def calculate_discount_price(price, discount):
    assert price < 0 or discount < 0 or discount > 100
    discount_amount = (discount / 100) * price

    return price - discount_amount

if __debug__:
   if not condition:
      raise AssertionError(message)

def delete_product(user, id):
    assert user.has_perm("del_product")
    Product.objects.delete(pk=id)

assert (1 > 2, "This condition is not valid")

import statistics

data = [3, 5, 7, 10, 15]

mean = statistics.mean(data)
print("میانگین:", mean)

median = statistics.median(data)
print("میانه:", median)

stdev = statistics.stdev(data)
print("انحراف معیار:", stdev)

variance = statistics.variance(data)
print("واریانس:", variance)

data = [3, 5, 5, 7, 5, 10, 15]

mode = statistics.mode(data)
print("مد:", mode)

(variable := expression)

if (n := len("hello")) > 4:
    print(f"String length is greater than 4: {n}")

n = len("hello")

if n > 4:
    print(f"String length is greater than 4 : {n}")

while (line := f.readline()):

# پردازش هر خط از فایل

if (match := re.search(pattern, text)):
    print(match.group()) 

if (numbers := [1, 2, 3]) and len(numbers) > 2:

# انجام کاری با لیست numbers

while True:
    command = input("> ")
    if command == 'exit':
        break
    print("Your command was:", command)

while (command := input("> ")) != "exit":
    print("Your command was:", command)

a = "salam
print(a)

SyntaxError: unterminated string literal

a = "salam"
if a:
print(a)

IndentationError: expected an indented block after 'if' statement

print(a)
a = 10

NameError: name 'a' is not defined

age = int(input("age: ")) #input: Yasin

ValueError: invalid literal for int() with base 10: 'Yasin'

print("hello" / 3)

TypeError: unsupported operand type(s) for /: 'str' and 'int'

with open("test.txt", "r") as t:
    t.read()

FileNotFoundError: [Errno 2] No such file or directory: 'test.txt'

import requests

ModuleNotFoundError: No module named 'requests'

names = ["Yasin", "Reza", "Navid"]
print(names[5])

IndexError: list index out of range

names = {'Yasin': '1', 'Reza': '2'}
print(names['3'])

KeyError: '3'

numbers = [1, 2, 3]
print(numbers.sum())

AttributeError: 'list' object has no attribute 'sum'

name = "Yasin"
def get_name():
    print(name)
    name = "ali"

    print(name)

get_name()

UnboundLocalError: cannot access local variable 'name' where it is not associated with a value

unicode_str = b"\u1234\u5678\u90AB"
print(decoded_str.decode("ascii"))

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe1 in position 0: ordinal not in range(128)

result = 5 / 0

ZeroDivisionError: division by zero

large_list = [0] * 1_000_000_000

import os

os.mkdir(r"C:\Windows\System32\new_directory")

number = int(input("enter a number: ")
print(number - 1)
print("bye")

ValueError: invalid literal for int() with base 10

try:
    number = int(input("enter a number: "))

except:
    print("the entry isn't an integer")

print("bye")

try:
    number = int(input("enter a number: "))
    print(1e3 / number)

except ValueError:
    print("the entry isn't an integer")

try:
    number = int(input("enter a number: "))
    print(1e3 / number)

except ValueError:
    print("the entry isn't an integer")

except ZeroDivisionError:
    print("entry cannot be zero")