# -*- coding: utf-8 -*-
"""
zask.utils
~~~~~~~~~~~~~~
(1) remove useless methods of werkzeug.utils
(2) add get_root_path
:copyright: (c) 2015 by the J5.
:license: BSD, see LICENSE for more details.
:copyright: (c) 2015 by the Werkzeug Team, see AUTHORS for more details.
:license: BSD, see LICENSE for more details.
"""
import os
import sys
[docs]def get_root_path(import_name):
mod = sys.modules.get(import_name)
if mod is not None and hasattr(mod, '__file__'):
return os.path.dirname(os.path.abspath(mod.__file__))
[docs]def import_string(import_name, silent=False):
"""Imports an object based on a string. This is useful if you want to
use import paths as endpoints or something similar. An import path can
be specified either in dotted notation (``xml.sax.saxutils.escape``)
or with a colon as object delimiter (``xml.sax.saxutils:escape``).
If `silent` is True the return value will be `None` if the import fails.
:param import_name: the dotted name for the object to import.
:param silent: if set to `True` import errors are ignored and
`None` is returned instead.
:return: imported object
"""
# force the import name to automatically convert to strings
# __import__ is not able to handle unicode strings in the fromlist
# if the module is a package
import_name = str(import_name).replace(':', '.')
try:
try:
__import__(import_name)
except ImportError:
if '.' not in import_name:
raise
else:
return sys.modules[import_name]
module_name, obj_name = import_name.rsplit('.', 1)
try:
module = __import__(module_name, None, None, [obj_name])
except ImportError:
# support importing modules not yet set up by the parent module
# (or package for that matter)
module = import_string(module_name)
try:
return getattr(module, obj_name)
except AttributeError as e:
raise ImportError(e)
except ImportError as e:
if not silent:
reraise(
ImportStringError,
ImportStringError(import_name, e),
sys.exc_info()[2])
[docs]class ImportStringError(ImportError):
"""Provides information about a failed :func:`import_string` attempt."""
#: String in dotted notation that failed to be imported.
import_name = None
#: Wrapped exception.
exception = None
def __init__(self, import_name, exception):
self.import_name = import_name
self.exception = exception
msg = (
'import_string() failed for %r. Possible reasons are:\n\n'
'- missing __init__.py in a package;\n'
'- package or module path not included in sys.path;\n'
'- duplicated package or module name taking precedence in '
'sys.path;\n'
'- missing module, class, function or variable;\n\n'
'Debugged import:\n\n%s\n\n'
'Original exception:\n\n%s: %s')
name = ''
tracked = []
for part in import_name.replace(':', '.').split('.'):
name += (name and '.') + part
imported = import_string(name, silent=True)
if imported:
tracked.append((name, getattr(imported, '__file__', None)))
else:
track = ['- %r found in %r.' % (n, i) for n, i in tracked]
track.append('- %r not found.' % name)
msg = msg % (import_name, '\n'.join(track),
exception.__class__.__name__, str(exception))
break
ImportError.__init__(self, msg)
def __repr__(self):
return '<%s(%r, %r)>' % (self.__class__.__name__, self.import_name,
self.exception)