Rewrite build script in Python

Just becuse

sessions/build.py

@@ -0,0 +1,24 @@
+import sys
+import os
+import subprocess
+
+
+def main():
+    if len(sys.argv) < 2:
+        sys.exit("Usage: build.py NUMBER")
+
+    number = sys.argv[1]
+
+    os.makedirs("build", exist_ok=True)
+    cmd = []
+    if sys.platform == "darwin":
+        # From mactex
+        cmd.append("texi2pdf")
+    else:
+        cmd.append("pdflatex")
+    cmd.append(f"../python-{number}")
+    subprocess.run(cmd, cwd="build", check=True)
+
+
+if __name__ == "__main__":
+    main()

sessions/build.sh

@@ -1,14 +0,0 @@
-#!/bin/zsh
-
-set -e
-
-if [[ -z $1 ]]; then
-  echo "Usage: build.sh NUMBER"
-  exit 1
-fi
-
-(
-  mkdir -p build
-  cd build
-  texi2pdf ../python-${1}.tex
-)