Make importlib backwards-compatible to Python 2.2 (but this is not promised to

last; just doing it to be nice).

Also fix a message for an exception.
This commit is contained in:
Brett Cannon 2009-02-03 21:13:05 +00:00
parent 7757d7bb51
commit 8bdd3b3dcf
1 changed files with 16 additions and 3 deletions

View File

@ -1,4 +1,6 @@
"""Backport of importlib.import_module from 3.x."""
# While not critical (and in no way guaranteed!), it would be nice to keep this
# code compatible with Python 2.3.
import sys
def _resolve_name(name, package, level):
@ -9,8 +11,14 @@ def _resolve_name(name, package, 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]
raise ValueError("'package' not set to a string")
try:
# rpartition is more "correct" and rfind is just as easy to use, but
# neither are in Python 2.3.
dot_rindex = package.rindex('.', level)[0]
base = package[:dot_rindex]
except ValueError:
base = package
if name:
return "%s.%s" % (base, name)
else:
@ -34,5 +42,10 @@ def import_module(name, package=None):
break
level += 1
name = _resolve_name(name[level:], package, level)
__import__(name)
# Try to import specifying the level to be as accurate as possible, but
# realize that keyword arguments are not found in Python 2.3.
try:
__import__(name, level=0)
except TypeError:
__import__(name)
return sys.modules[name]