advent_of_code_2021

day01_part2.py (1329B)

---

 #!/usr/bin/env python
 """For part 2, we use the same data but sum over a three-element sliding window
 before calculating diffs as before."""
 
 # This is my first Advent of Code, so I wasn't sure how closely related the two
 # parts would be, so I didn't know how much code reuse would be typical. I like
 # that I can just `import` a previous solution and get any useful definitions
 # from there (though I'll try to be mindful of what should go into `utils.py`.
 
 from day01_part1 import (download_input_data,
                          calculate_depth_diffs,
                          count_depth_increases)
 
 def calculate_sliding_sum(depth_series):
     """Given a pandas series of depths, returns a new series where each element
     has been replaced by the sum of that element and the preceding two
     elements"""
     # It's not actually necessary to calculate the rolling sum to solve the
     # puzzle, but this is great pandas practice for me
     return depth_series.rolling(window=3).sum()
 
 def solve_puzzle():
     """Return the numeric solution to the puzzle"""
     return count_depth_increases(
         calculate_depth_diffs(
             calculate_sliding_sum(download_input_data()['depth'])
         )
     )
 
 if __name__ == "__main__":
     print("Number of depth increases (using a sliding window):",
           solve_puzzle())