One-line to multiline block iterators

python_iterators.py

from itertools import chain, repeat

# Define the inventory as a dictionary
inventory = {
    "banana": 3,
    "apple": 2,
    "pear": 1,
    "berry": 4,
}

# Use itertools.chain and itertools.repeat to replicate the fruit names
inventory_list = list(chain.from_iterable(repeat(fruit.upper(), quantity) for fruit, quantity in inventory.items()))

print(inventory_list)

## INTO Version with logging

from itertools import chain, repeat

# Define the inventory as a dictionary
inventory = {
    "banana": 3,
    "apple": 2,
    "pear": 1,
    "berry": 4,
}

def log_and_uppercase(fruit):
    print(f"Processing: {fruit}")  # Log statement before uppercasing
    return fruit.upper()

# Use a generator expression with a function call for logging and uppercasing
inventory_list = list(chain.from_iterable(repeat(log_and_uppercase(fruit), quantity) for fruit, quantity in inventory.items()))

print(inventory_list)

ruby_iterators.rb

inventory = {
  'banana' => 3,
  'apple' => 2,
  'pear' => 1,
  'berry' => 4
}

inventory_list = inventory.flat_map { |fruit, quantity| [fruit.upcase] * quantity }

puts inventory_list.inspect

## Version with logging.

inventory = {
  'banana' => 3,
  'apple' => 2,
  'pear' => 1,
  'berry' => 4
}

inventory_list = inventory.flat_map do |fruit, quantity|
  puts "Processing: #{fruit}"  # Log statement before uppercasing
  [fruit.upcase] * quantity
end

puts inventory_list.inspect

rust_iterators.rs

use std::collections::HashMap;

fn main() {
    let inventory = HashMap::from([("banana", 3), ("apple", 2), ("pear", 1), ("berry", 4)]);

    // Transform and repeat each fruit name in uppercase based on its quantity
    let inventory_list: Vec<String> = inventory
        .iter()
        .flat_map(|(fruit, &quantity)| std::iter::repeat(fruit.to_uppercase()).take(quantity))
        .collect();

    println!("{:?}", inventory_list);
}
      
//into:
use std::collections::HashMap;

fn main() {
    let inventory = HashMap::from([
        ("banana", 3),
        ("apple", 2),
        ("pear", 1),
        ("berry", 4),
    ]);

    let inventory_list: Vec<String> = inventory.iter()
        .flat_map(|(fruit, &quantity)| {
            std::iter::repeat_with(|| {
                println!("Processing: {}", fruit); // Log statement before uppercasing
                fruit.to_uppercase()
            })
            .take(quantity)
        })
        .collect();

    println!("{:?}", inventory_list);
}