Advanced Python

add = lambda a, b: a + b
print(add(10, 20))

numbers = [1, 2, 3, 4, 5]
squares = list(map(lambda x: x * x, numbers))
print(squares)

numbers = [1, 2, 3, 4, 5, 6]
evens = list(filter(lambda x: x % 2 == 0, numbers))
print(evens)

students = [
    ("Ravi", 75),
    ("Anita", 92),
    ("Kiran", 81)
]

result = sorted(students, key=lambda student: student[1])
print(result)

from functools import reduce

numbers = [10, 20, 30, 40]
total = reduce(lambda a, b: a + b, numbers)
print(total)

numbers = [10, 20, 30]
iterator = iter(numbers)

print(next(iterator))
print(next(iterator))
print(next(iterator))

numbers = [10, 20]
iterator = iter(numbers)

try:
    while True:
        print(next(iterator))
except StopIteration:
    print("No more values")

class Countdown:
    def __init__(self, start):
        self.current = start

    def __iter__(self):
        return self

    def __next__(self):
        if self.current <= 0:
            raise StopIteration
        value = self.current
        self.current -= 1
        return value

for number in Countdown(5):
    print(number)

def numbers():
    for i in range(1, 6):
        yield i

for n in numbers():
    print(n)

def even_numbers(limit):
    for i in range(2, limit + 1, 2):
        yield i

print(list(even_numbers(10)))

def values():
    yield "A"
    yield "B"
    yield "C"

g = values()
print(next(g))
print(next(g))
print(next(g))

squares = (x * x for x in range(1, 6))

for value in squares:
    print(value)

def read_lines(filename):
    with open(filename, encoding="utf-8") as file:
        for line in file:
            yield line.strip()

for line in read_lines("data.txt"):
    print(line)

def logger(func):
    def wrapper():
        print("Function started")
        func()
        print("Function finished")
    return wrapper

@logger
def greet():
    print("Hello")

greet()

def logger(func):
    def wrapper(*args, **kwargs):
        print("Calling function")
        result = func(*args, **kwargs)
        print("Function completed")
        return result
    return wrapper

@logger
def add(a, b):
    return a + b

print(add(5, 7))

from functools import wraps

def logger(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        return func(*args, **kwargs)
    return wrapper

@logger
def greet():
    """Greets the user."""
    print("Hello")

print(greet.__name__)
print(greet.__doc__)

import time
from functools import wraps

def timer(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        start = time.perf_counter()
        result = func(*args, **kwargs)
        end = time.perf_counter()
        print("Time:", end - start)
        return result
    return wrapper

@timer
def work():
    total = sum(range(100000))
    return total

print(work())

from functools import wraps

def positive_only(func):
    @wraps(func)
    def wrapper(x):
        if x <= 0:
            raise ValueError("Number must be positive")
        return func(x)
    return wrapper

@positive_only
def square(x):
    return x * x

print(square(5))

words = ["python", "sql", "power bi"]
result = list(map(str.upper, words))
print(result)

names = ["Ravi", "Anita", "Kiran", "Suresh"]
result = list(filter(lambda name: len(name) > 4, names))
print(result)

from functools import reduce

numbers = [2, 3, 4, 5]
product = reduce(lambda a, b: a * b, numbers)
print(product)

def apply_operation(a, b, operation):
    return operation(a, b)

def multiply(x, y):
    return x * y

print(apply_operation(6, 7, multiply))

def multiplier(factor):
    def multiply(number):
        return number * factor
    return multiply

double = multiplier(2)
print(double(10))

def counter():
    count = 0

    def increment():
        nonlocal count
        count += 1
        return count

    return increment

c = counter()
print(c())
print(c())
print(c())

from functools import wraps

def message(text):
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            print(text)
            return func(*args, **kwargs)
        return wrapper
    return decorator

@message("Starting task")
def task():
    print("Task running")

task()

def numbers():
    for i in range(1, 11):
        yield i

evens = (x for x in numbers() if x % 2 == 0)
squares = (x * x for x in evens)

print(list(squares))

from functools import wraps

def require_name(func):
    @wraps(func)
    def wrapper(name):
        if not name.strip():
            raise ValueError("Name cannot be empty")
        return func(name)
    return wrapper

@require_name
def greet(name):
    return f"Hello {name}"

print(greet("Naveen"))

class NumberRange:
    def __init__(self, start, stop):
        self.current = start
        self.stop = stop

    def __iter__(self):
        return self

    def __next__(self):
        if self.current >= self.stop:
            raise StopIteration
        value = self.current
        self.current += 1
        return value

for n in NumberRange(1, 5):
    print(n)

def fibonacci(count):
    a, b = 0, 1
    for _ in range(count):
        yield a
        a, b = b, a + b

print(list(fibonacci(10)))

from functools import wraps

def count_calls(func):
    calls = 0

    @wraps(func)
    def wrapper(*args, **kwargs):
        nonlocal calls
        calls += 1
        print("Call number:", calls)
        return func(*args, **kwargs)

    return wrapper

@count_calls
def greet(name):
    print("Hello", name)

greet("A")
greet("B")
greet("C")