What is the any() function in Python?

any(iterable)

# At least one element is True
result = any([False, False, True, False])
print(result)  # True

# All elements are False
result = any([False, False, False])
print(result)  # False

# Empty list
result = any([])
print(result)  # False

# With numeric values
result = any([0, 0, 0, 1])
print(result)  # True (1 is truthy)

# With strings
result = any(["", "", "hello"])
print(result)  # True ("hello" is truthy)

# Check if at least one number is even
numbers = [1, 3, 5, 7, 8, 9]
result = any(n % 2 == 0 for n in numbers)
print(result)  # True (8 is even)

# Check if a list contains at least one negative number
values = [10, 25, -3, 42, 7]
has_negative = any(v < 0 for v in values)
print(has_negative)  # True (-3 is negative)

# Check if a word starts with an uppercase letter
words = ["python", "java", "Ruby", "go"]
has_uppercase = any(word[0].isupper() for word in words)
print(has_uppercase)  # True ("Ruby")

# By default, any() iterates over keys
my_dict = {0: "zero", "": "empty", "key": "value"}
result = any(my_dict)
print(result)  # True ("key" is truthy)

# Test the dictionary values
grades = {"Alice": 0, "Bob": 0, "Charlie": 15}
someone_has_grade = any(my_dict.values())
print(someone_has_grade)  # True

# Check if at least one student passed
students = {"Alice": 8, "Bob": 12, "Charlie": 6}
someone_passed = any(grade >= 10 for grade in students.values())
print(someone_passed)  # True (Bob has 12)

# Check if a string contains at least one digit
text = "Hello world 2024"
contains_digit = any(c.isdigit() for c in text)
print(contains_digit)  # True

# Check if a string contains at least one uppercase letter
password = "mypassword"
has_uppercase = any(c.isupper() for c in password)
print(has_uppercase)  # False

# Password validation
def validate_password(pwd):
    has_upper = any(c.isupper() for c in pwd)
    has_lower = any(c.islower() for c in pwd)
    has_digit = any(c.isdigit() for c in pwd)
    has_special = any(not c.isalnum() for c in pwd)
    long_enough = len(pwd) >= 8
    return all([has_upper, has_lower, has_digit, has_special, long_enough])

print(validate_password("MyP@ss1!"))  # True
print(validate_password("weak"))      # False

numbers = [1, 2, 0, 4, 5]

print(any(numbers))  # True (at least one is truthy)
print(all(numbers))  # False (0 is falsy)

# All positive vs at least one positive
values = [-1, -2, 3, -4]
print(any(v > 0 for v in values))  # True (3 > 0)
print(all(v > 0 for v in values))  # False (some are negative)

# With an empty iterable
print(any([]))  # False
print(all([]))  # True (logical convention)

def my_any(iterable):
    for element in iterable:
        if element:
            return True
    return False

# Test
print(my_any([0, False, None, "", 42]))  # True
print(my_any([0, False, None, ""]))      # False
print(my_any([]))                         # False

# Check if at least one file has a dangerous extension
files = ["report.pdf", "image.png", "script.exe", "notes.txt"]
dangerous_extensions = [".exe", ".bat", ".cmd"]

has_dangerous_file = any(
    file.endswith(ext)
    for file in files
    for ext in dangerous_extensions
)
print(has_dangerous_file)  # True (script.exe)

# Check if a user has the required permissions
user_permissions = ["read", "comment"]
admin_permissions = ["write", "delete", "admin"]

is_admin = any(p in admin_permissions for p in user_permissions)
print(is_admin)  # False

class Product:
    def __init__(self, name, stock):
        self.name = name
        self.stock = stock

    def __bool__(self):
        return self.stock > 0

    def __repr__(self):
        return f"Product('{self.name}', stock={self.stock})"

products = [
    Product("Keyboard", 0),
    Product("Mouse", 0),
    Product("Monitor", 5),
]

# Check if at least one product is in stock
print(any(products))  # True (Monitor has stock)

# With an explicit condition
print(any(p.stock > 10 for p in products))  # False

# With map()
numbers = ["10", "abc", "20", "xyz"]

def is_numeric(s):
    try:
        int(s)
        return True
    except ValueError:
        return False

result = any(map(is_numeric, numbers))
print(result)  # True

# With a lambda function
my_list = [1, 3, 5, 7, 9]
has_even = any(map(lambda x: x % 2 == 0, my_list))
print(has_even)  # False (all odd)

# ❌ any() doesn't tell you WHICH element is true
result = any(n > 100 for n in numbers)

# ✅ If you need the element, use next()
element = next((n for n in numbers if n > 100), None)

# ✅ Or a for loop
for n in numbers:
    if n > 100:
        print(f"Found: {n}")
        break

import time

# Performance comparison: loop vs any()
numbers = list(range(1_000_000))

# With any() - short-circuits at the first truthy element
start = time.time()
result = any(n > 0 for n in numbers)
end = time.time()
print(f"any(): {end - start:.6f}s")  # Very fast (short-circuit)

# With a manual loop
start = time.time()
found = False
for n in numbers:
    if n > 0:
        found = True
        break
end = time.time()
print(f"Loop: {end - start:.6f}s")  # Similar but less readable