Python Loops Coding Exercise Solution

loops.py

def sing(num_bottles):
    #TODO: Add your code to achieve the desired output and pass the challenge. 
    #NOTE: The f String method of String Interpolation does not work. 
    lyrics = []
    for num in range(num_bottles, 0, -1):
        lyrics.append('{num} bottles of beer on the wall, {num} bottles of beer.'.format(num = num))
        lyrics.append('Take one down and pass it around, {num} bottles of beer on the wall.'.format(num = num - 1))
        lyrics.append('')
        
    return lyrics
    

Here is an alternative

def sing(num_bottles):
        counter=num_bottles
        while counter > 0:
             print(counter,' bottles of beer on the wall, ', counter, 'bottles of beer')
             print('Take one down and pass it around, ', counter-1, 'bottles of beer on the wall')
             counter = counter -1

Here is another alternative

def sing(num_bottles):
    lirics = []
    for n in range(0, num_bottles, 1):
        if num_bottles - n == 0:
            break
        lirics.append(f'{num_bottles - n} bottles of beer on the wall. {num_bottles - n} bottles of beer')
        lirics.append(f'Take one down and pass it around, {num_bottles - n-1} bottles of beer on the wall')
        lirics.append('')

    return lirics

I don't understand the notation with curly braces why we need them and how it works,

why we need to use syntax .format(num = num)

why we need to specifiy .format(num = num -1) to decrease with -1,

why is not enough to have only in function range() the third parameter which his purpose is exactly to specify increment/decrement step

I've got issue with exercise 6. My answer was correct and still saying wrong...

Here's another example that's a bit simpler:

def sing(num_bottles):
    output = []
    for n in reversed(range(num_bottles + 1)):
        if(n == 0) :
            break;
        output.append('{} bottles of beer on the wall, {} bottles of beer.'.format(n, n))
        output.append('Take one down and pass it around, {} bottles of beer on the wall.'.format(n - 1))
        output.append('');
        
    return output