nix: migrate to 'ruff'

Having just the one tool is better.

Incidentally, this fixes the ternary formatting, which was messed up in
recent `black` versions.

.isort.cfg

@@ -1,2 +0,0 @@
-[settings]
-profile=black

2020/d17/ex1/ex1.py

@@ -41,7 +41,6 @@ def update(grid: Grid) -> Grid:
 
 
 def solve(grid: Grid) -> int:
-
     for __ in range(6):
         grid = update(grid)
 

2020/d17/ex2/ex2.py

@@ -41,7 +41,6 @@ def update(grid: Grid) -> Grid:
 
 
 def solve(grid: Grid) -> int:
-
     for __ in range(6):
         grid = update(grid)
 

2021/d25/ex1/ex1.py

@@ -63,7 +63,9 @@ def solve(input: List[str]) -> int:
                     (
                         "v"
                         if Point(x, y) in map.south
-                        else ">" if Point(x, y) in map.east else "."
+                        else ">"
+                        if Point(x, y) in map.east
+                        else "."
                     )
                     for y in range(map.dimensions.y)
                 )

2022/d07/ex1/ex1.py

@@ -8,7 +8,6 @@ FileSystem = dict[str, Union[int, "FileSystem"]]
 
 def solve(input: list[str]) -> int:
     def build_tree(input: list[str], i: int = 0) -> tuple[FileSystem, int]:
-
         fs: FileSystem = {}
 
         while i < len(input):

2022/d07/ex2/ex2.py

@@ -8,7 +8,6 @@ FileSystem = dict[str, Union[int, "FileSystem"]]
 
 def solve(input: list[str]) -> int:
     def build_tree(input: list[str], i: int = 0) -> tuple[FileSystem, int]:
-
         fs: FileSystem = {}
 
         while i < len(input):

flake.nix

@@ -39,17 +39,17 @@
             src = self;
 
             hooks = {
-              black = {
-                enable = true;
-              };
-
-              isort = {
-                enable = true;
-              };
-
               nixpkgs-fmt = {
                 enable = true;
               };
+
+              ruff = {
+                enable = true;
+              };
+
+              ruff-format = {
+                enable = true;
+              };
             };
           };
         };
@@ -57,12 +57,11 @@
         devShell = pkgs.mkShell {
           buildInputs = with pkgs; [
             (python3.withPackages (ps: with ps; [
-              black
-              isort
               mypy
               z3
             ]))
             pyright
+            ruff
           ];
 
           inherit (self.checks.${system}.pre-commit) shellHook;

ruff.toml

@@ -0,0 +1,8 @@
+[lint]
+extend-select = [
+    "I", # Import sorting is a lint check
+]
+ignore = [
+    "E731", # Assigning lambdas is sometimes more readable
+    "E741", # Ambiguous variable names are good enough actually
+]