'Returns a dict of installed packages that Zappa cares about.'

@staticmethod
def get_installed_packages(site_packages, site_packages_64):

    import pip
    package_to_keep = []
    if os.path.isdir(site_packages):
        package_to_keep += os.listdir(site_packages)
    if os.path.isdir(site_packages_64):
        package_to_keep += os.listdir(site_packages_64)
    installed_packages = {package.project_name.lower(): package.version for package in pip.get_installed_distributions() if ((package.project_name in package_to_keep) or (package.location in [site_packages, site_packages_64]))}
    return installed_packages
