Add script to downstream PRs.

bin/downstream_pr.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+if [ -z "$1" ]
+  then
+    echo "Usage: downstream_pr.sh <PR_number>"
+    echo "Will create a new branch, apply changes, and create a new PR"
+    exit 1
+fi
+
+set -e
+
+git checkout main
+git pull origin main
+git checkout -b downstream_$1
+
+echo "Downloading patch..."
+wget -O $1.patch https://patch-diff.githubusercontent.com/raw/aesara-devs/aesara/pull/$1.patch
+
+echo "Replacing aesara strings..."
+declare -a replace_strings=(
+    "s/aesara/pytensor/g"
+    "s/Aesara/PyTensor/g"
+#    "s/import pytensor.tensor as at/import pytensor.tensor as pt/g"
+    "s/at\./pt./g"
+#    "s/from pytensor import tensor as pt/from pytensor import tensor as pt/g"
+)
+
+for replace in "${replace_strings[@]}"; do
+    find . -name "*$1.patch" -type f -exec sed -i -e "/png/!$replace" {} \;
+done
+
+echo "Applying patch..."
+git am -3 --reject $1.patch
+
+echo "Running pre-commit"
+pre-commit run --all
+
+git push origin downstream_$1
+
+gh pr create --repo pymc-devs/pytensor --title "Downstreaming $1" --body "Downstreaming https://github.com/aesara-devs/aesara/pull/$1"