nix: add tools to devShell

2019/d07/ex1/ex1.py

@@ -1,5 +1,9 @@
 #!/usr/bin/env python
 
+# Mypy has issues with assigning Callable to fields of objects
+# See https://github.com/python/mypy/issues/708
+# type: ignore
+
 import itertools
 import sys
 from copy import deepcopy

flake.nix

@@ -56,6 +56,9 @@
 
         devShell = pkgs.mkShell {
           buildInputs = with pkgs; [
+            pkgs.python3Packages.black
+            pkgs.python3Packages.isort
+            pkgs.python3Packages.mypy
             python3
           ];