heroku-buildpack-python/bin/detect

#!/usr/bin/env bash

# This script serves as the 
# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python) 
# detector. 
# 
# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an 
# adapter between a Python application and Heroku's runtime.

# ## Usage
# Compiling an app into a slug is simple:
# 
#     $ bin/detect <build-dir> <cache-dir>

BUILD_DIR=$1

# Exit early if app is clearly not Python.
if [ ! -f $BUILD_DIR/requirements.txt ] && [ ! -f $BUILD_DIR/setup.py ]; then
  exit 1
fi

# If only `setup.py`, assume that the app is not Django.
if [ ! -f $BUILD_DIR/requirements.txt ]; then
  echo Python
  exit 0
fi

# `Python/Django` if `**/settings.py` is present and `django` exists in 
# `requirements.txt`.
#
# Otherwise, `Python`.

ls $BUILD_DIR/**/settings.py &> /dev/null && (grep -Fiq "django" $BUILD_DIR/requirements.txt) && echo Python/Django || echo Python