Advent of Code 2021 Day 13 - Written for: https://blog.zefhub.io/solving-advent-of-code-using-zefops/

advent-of-code-day13.py

from zef.ops import *       # don't forget to import ZefOps module from zef

str_points: str = """..."""                  
str_folds:  str = """..."""                    

points = (str_points
| split["\n"]                # ["897,393", "...]
| map[split[","] | map[int]] # [[897,393], [...]
| collect)

foldings = (str_folds
| split["\n"]                                   # ["fold along y=6", ...]
| map[split[" "] | last | split["="]]           # [["y", "6"], [...]
| map[lambda p: (int(p[0] == 'y'), int(p[1]))]  # [(1, 6), ..]       
| collect)


def fold(points: set, fold_info: tuple) -> set:
    axis, val = fold_info
    new_coordinate = lambda p: ( (p[0], val - (p[axis] - val)) if axis == 1 else (val - (p[axis] - val), p[1]) )
    dispatch = lambda p: new_coordinate(p) if p[axis] > val else tuple(p)
    return set(
        points
        | map[dispatch]
        | collect
    )
  
def output(points):
   for y in range((points | map[second] | max | collect) + 1):
       for x in range((points | map[first] | max | collect) + 1):
           if (x,y) in points: print("🟨🟨", end="")
           else: print("⬜️⬜️", end="")
       print
      
# Part 1 - Result   
fold(points, foldings[0]) | length | run[print]    
# Part 2 - Result
foldings | reduce[fold][points] | run[output]