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Python Code Samples

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7 matches
Functions & basics easy

How to Compose Two Functions into a Single Callable in Python

Combine two Python functions into a single callable using a compose helper, then apply the chained call.

functions composition lambda
Python
def add_one(x):
    return x + 1

def double(x):
    return x * 2

def compose(f, g):
    return lambda x: f(g(x))

add_then_double = compose(double, add_one)
double_then_add = compose(add_one, double)

result1 = add_then_double(5)
result2 = double_then_add(5)

print(f"add_one then double(5) = {result1}")
print(f"doub…
12 0 Open
Functions & basics easy

How to Pass a Function as a Callback to map and filter in Python

Shows how to apply custom functions to every element of a list using map and filter callbacks in Python.

map filter callbacks
Python
def double(x):
    return x * 2

def is_even(x):
    return x % 2 == 0

if __name__ == "__main__":
    numbers = [1, 2, 3, 4, 5]
    doubled = list(map(double, numbers))
    evens = list(filter(is_even, numbers))
    print("Original:", numbers)
    print("Doubled:", doubled)
    print("Evens:", evens)
16 0 Open
Functions & basics easy

How to Pipe Data Through a List of Transform Functions in Python

Applies a sequence of functions to an initial value using functools.reduce, creating a reusable pipe utility.

functions functional reduce
Python
from functools import reduce

def pipe(data, *transforms):
    return reduce(lambda value, func: func(value), transforms, data)

def double(x):
    return x * 2

def add_one(x):
    return x + 1

def to_string(x):
    return f"Result: {x}"

if __name__ == "__main__":
    initial = 5
    result = pipe(initial, double, …
13 0 Open
Functions & basics easy

How to Use functools.reduce in Python

Apply functools.reduce with operator functions and lambda expressions to aggregate lists into sums, products, maximums, and concatenated strings.

reduce functools lambda
Python
from functools import reduce
import operator

# Sum all numbers in a list using reduce
numbers = [1, 2, 3, 4, 5]
sum_result = reduce(operator.add, numbers)

# Find the maximum value using reduce
max_result = reduce(lambda a, b: a if a > b else b, numbers)

# Multiply all numbers using reduce
product_result = reduce(la…
12 0 Open
Algorithms & data structures easy

How to Combine filter and map with a List Comprehension in Python

This Python code demonstrates how to combine filtering and mapping in a single list comprehension and shows the equivalent filter() and map() approach.

list-comprehension filter map
Python
def square(x):
    return x * x

def is_even(x):
    return x % 2 == 0

numbers = [1, 2, 3, 4, 5, 6, 7, 8]

result = [square(x) for x in numbers if is_even(x)]

print(f"Original numbers: {numbers}")
print(f"Squares of even numbers: {result}")

# Combined filter + map equivalent
filtered = filter(is_even, numbers)
mapp…
13 0 Open
Comprehensions & generators easy

How to Use starmap() to Unpack Tuple Arguments in Python

Use itertools.starmap to apply a function to each tuple in an iterable, unpacking tuple elements as separate arguments and returning an iterator of results.

itertools starmap generators
Python
from itertools import starmap

def multiply(a, b):
    return a * b

if __name__ == "__main__":
    pairs = [(2, 3), (4, 5), (6, 7), (8, 9)]
    results = list(starmap(multiply, pairs))
    print(results)
14 0 Open
Data pipelines & processing easy

Pipeline stage compose functions left to right in Python

Compose multiple functions into a left-to-right pipeline so each stage receives the output of the previous one.

composition pipeline functional
Python
def compose(*funcs):
    """Compose functions left to right: compose(f, g, h)(x) == h(g(f(x)))"""
    def composed(arg):
        result = arg
        for func in funcs:
            result = func(result)
        return result
    return composed

if __name__ == "__main__":
    def add_one(x):
        return x + 1

    …
16 0 Open

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