78 lines
2 KiB
Markdown
78 lines
2 KiB
Markdown
# Python advent learnings
|
|
|
|
### Construct paths without hard-coding absolute path
|
|
|
|
```py
|
|
puzzle_input_path = os.path.join(os.path.dirname(__file__), "data/test_input.txt")
|
|
|
|
```
|
|
|
|
### Read file by line and store in variable
|
|
|
|
```py
|
|
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:
|
|
|
|
```py
|
|
if all(element >= 0 for element in array):
|
|
print('All elements greater than 0')
|
|
```
|
|
|
|
Check if any element is less than 0:
|
|
|
|
```py
|
|
if any(element < 0 for element in array):
|
|
print('There is an element that is less than 0')
|
|
```
|
|
|
|
### Check for substring:
|
|
|
|
```py
|
|
text = "latest test"
|
|
if "test" in text:
|
|
return True
|
|
```
|
|
|
|
### Control flow in loop
|
|
|
|
```py
|
|
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
|
|
|
|
```py
|
|
games = [item.strip().split() for game in games for item in game.split(",")]
|
|
```
|