code: def get_deps_list(self, pkg_name, installed_distros=None):
          
          # https://github.com/Miserlou/Zappa/issues/1478.  Using `pkg_resources`
          # instead of `pip` is the recommended approach.  The usage is nearly
          # identical.
          import pkg_resources
          deps = []
          if not installed_distros:
              installed_distros = pkg_resources.WorkingSet()
          for package in installed_distros:
              if package.project_name.lower() == pkg_name.lower():
                  deps = [(package.project_name, package.version)]
                  for req in package.requires():
                      deps += self.get_deps_list(pkg_name=req.project_name, installed_distros=installed_distros)
          return list(set(deps))
docs: For a given package, returns a list of required packages. Recursive.