python

#!/usr/bin/env bash

# -----------------------------------------------------------------------------
# uv python shim -- v1.1.0
# https://github.com/newbery/uv-python-shims
#
# - Mimics the pyenv python shim behavior.
# - Uses `uv python find` for discovery (including .python-version handling).
# - If invoked as python3.X, enforces major.minor = 3.X by re-finding with 3.X.
# - If a suitable python cannot be found, this will fail with an error message.
# -----------------------------------------------------------------------------

set -euo pipefail

FLAGS=(--resolve-links)

# Uncomment to ignore virtual environments
# Note that an 'activated' virtual environment will likely shadow this shim
# so this flag is only useful for ignoring non-activated virtual environments.
# FLAGS+=(--system)

# Uncomment to ignore '.python-version' files
# FLAGS+=(--no-config)

# Uncomment to avoid discovering a project or workspace
# FLAGS+=(--no-project)

# Uncomment to force uv-managed pythons only
# FLAGS+=(--managed-python)

# Pop shim dir out of PATH to avoid recursion
shim_dir="$(cd "$(dirname "$0")" && pwd)"
path=""
IFS=':' read -r -a parts <<< "${PATH:-}"
for p in "${parts[@]}"; do
  [[ -z "$p" ]] && continue
  [[ "$p" == "$shim_dir" ]] && continue
  path="${path:+$path:}$p"
done

uv_find() {
  PATH="$path" uv python find "${FLAGS[@]}" "$@"
}

uv_find_version() {
  PATH="$path" uv python find --show-version "${FLAGS[@]}"
}

major_minor() {
  local v="$1"
  IFS='.' read -r a b _rest <<< "$v"
  printf '%s.%s\n' "$a" "$b"
}

py=""

# Try to extract major.minor override from shim name or environment variable:
#   python3.11   -> 3.11
#   python3.11.2 -> 3.11
shim_prefix=""
invoked_as="${UV_PYTHON_SHIM_INVOKED_AS:-$(basename "$0")}"
if [[ "$invoked_as" =~ ^python3\.([0-9]+)(\.([0-9]+))?$ ]]; then
  shim_prefix="3.${BASH_REMATCH[1]}"
fi

# If major.minor override is given, test if found version matches
if [[ -n "$shim_prefix" ]]; then
  found_prefix=""
  found_version="$(uv_find_version 2>/dev/null || true)"
  if [[ -n "$found_version" ]]; then
    found_prefix="$(major_minor "$found_version")"
  fi

  # If not a match, let's defer to the result using the shim prefix
  if [[ "$found_prefix" != "$shim_prefix" ]]; then
    py="$(uv_find "$shim_prefix")"
  fi
fi

# Otherwise, the default `uv python find` result is good enough.
if [[ -z "$py" ]]; then
  py="$(uv_find)"
fi

exec env PATH="$path" "$py" "$@"