advent_of_code_2021

day01_part1.py (1604B)

---

 #!/usr/bin/env python
 """For Day 1, part 1 of the 2021 Advent of Code, we're simply inspecting a
 stream of numbers and counting the number of times that an item in the stream
 is greater than the preceding element."""
 
 # As I work through these problems, I will often decide whether I want to use a
 # pure Python approach, or whether I want to use numpy/pandas. I feel like I
 # have more familiarity with the language in general than these libraries, so
 # I'm going to lean on them more heavily than might be necessary. For instance,
 # I could make a `lag` iterator and `zip` the original stream with its lagged
 # version, but I'm not doing that here.
 
 from io import StringIO
 import pandas as pd
 from utils import get_puzzle_input
 
 def download_input_data():
     """Downloads the data for the day and returns a pandas data frame with a
     single column named `depth`"""
     return pd.read_csv(StringIO(get_puzzle_input(1)),
                        names=('depth',))
 
 def calculate_depth_diffs(depth_series):
     """Given a pandas series of depths, returns the difference between each
     element and the preceding one"""
     return depth_series - depth_series.shift(1)
 
 def count_depth_increases(depth_diff_series):
     """Given a pandas series of depth differences, count the number of
     increases"""
     return (depth_diff_series > 0).sum()
 
 def solve_puzzle():
     """Return the numeric solution to the puzzle"""
     return count_depth_increases(
         calculate_depth_diffs(download_input_data()['depth'])
     )
 
 if __name__ == "__main__":
     print("Number of depth increases:", solve_puzzle())