cpython/Lib/importlib.py

39 lines
1.2 KiB
Python

"""Backport of importlib.import_module from 3.x."""
import sys
def _resolve_name(name, package, level):
"""Return the absolute name of the module to be imported."""
level -= 1
try:
if package.count('.') < level:
raise ValueError("attempted relative import beyond top-level "
"package")
except AttributeError:
raise ValueError("__package__ not set to a string")
base = package.rsplit('.', level)[0]
if name:
return "{0}.{1}".format(base, name)
else:
return base
def import_module(name, package=None):
"""Import a module.
The 'package' argument is required when performing a relative import. It
specifies the package to use as the anchor point from which to resolve the
relative import to an absolute import.
"""
if name.startswith('.'):
if not package:
raise TypeError("relative imports require the 'package' argument")
level = 0
for character in name:
if character != '.':
break
level += 1
name = _resolve_name(name[level:], package, level)
__import__(name)
return sys.modules[name]