Python advent learnings

Construct paths without hard-coding absolute path

puzzle_input_path = os.path.join(os.path.dirname(__file__), "data/test_input.txt")

Read file by line and store in variable

puzzle_input_path = os.path.join(os.path.dirname(__file__), "data/test_input.txt")

def getPuzzleInput(file_path):
    with open(file_path, "r") as file:
        return [line.strip() for line in file]


puzzle_input = getPuzzleInput(puzzle_input_path)

Conditional tests for members of arrays

Check that all elements are greater than zero:

if all(element >= 0 for element in array):
    print('All elements greater than 0')

Check if any element is less than 0:

if any(element < 0 for element in array):
    print('There is an element that is less than 0')

Check for substring:

text = "latest test"
if "test" in text:
    return True

Control flow in loop

for counter_values in games:
    colour = counter_values[1]
    count = int(counter_values[0])
    if colour in initial_values.keys() and count > initial_values[colour]:
        break
else:
    valid_games_count += game_number

The use of the else clause here is a special feature of Python. The else clause after a for loop will normally only execute when the loop has finished iterating over the list, but not when the loop is terminated by a break statement.

The else clause is executed if the for loop completes normally. If the break statement is executed (i.e., if any count in counter_values is greater than the corresponding count in initial_values), the for loop is terminated and the else clause is skipped.

Here the combination of a for loop and the break statement creates if, else logic. If the break condition is not reached, then the else block runs for every iteration of the loop.

Multiple loop in list comprehension

games = [item.strip().split() for game in games for item in game.split(",")]

2 KiB Raw Blame History