79 lines
2 KiB
Markdown
79 lines
2 KiB
Markdown
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# Python advent learnings
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### Construct paths without hard-coding absolute path
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```py
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puzzle_input_path = os.path.join(os.path.dirname(__file__), "data/test_input.txt")
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```
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### Read file by line and store in variable
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```py
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puzzle_input_path = os.path.join(os.path.dirname(__file__), "data/test_input.txt")
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def getPuzzleInput(file_path):
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with open(file_path, "r") as file:
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return [line.strip() for line in file]
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puzzle_input = getPuzzleInput(puzzle_input_path)
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```
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### Conditional tests for members of arrays
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Check that all elements are greater than zero:
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```py
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if all(element >= 0 for element in array):
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print('All elements greater than 0')
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```
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Check if any element is less than 0:
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```py
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if any(element < 0 for element in array):
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print('There is an element that is less than 0')
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```
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### Check for substring:
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```py
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text = "latest test"
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if "test" in text:
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return True
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```
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### Control flow in loop
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```py
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for counter_values in games:
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colour = counter_values[1]
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count = int(counter_values[0])
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if colour in initial_values.keys() and count > initial_values[colour]:
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break
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else:
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valid_games_count += game_number
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```
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The use of the `else` clause here is a special feature of Python. The `else`
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clause after a `for` loop will normally only execute when the loop has finished
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iterating over the list, but not when the loop is terminated by a `break`
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statement.
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The `else` clause is executed if the `for` loop completes normally. If the
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`break` statement is executed (i.e., if any count in `counter_values` is greater
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than the corresponding count in `initial_values`), the `for` loop is terminated
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and the `else` clause is skipped.
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Here the combination of a `for` loop and the `break` statement creates
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`if, else` logic. If the break condition is not reached, then the `else` block
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runs for every iteration of the loop.
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### Multiple loop in list comprehension
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```py
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games = [item.strip().split() for game in games for item in game.split(",")]
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```
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