Deprecated since version 2.6: The imputil
module has been removed in Python 3.
This module provides a very handy and useful mechanism for custom import
hooks. Compared to the older ihooks
module, imputil
takes a dramatically simpler and more straight-forward approach to custom import
functions.
class imputil.ImportManager([fs_imp])
Manage the import process.
install([namespace])
Install this ImportManager into the specified namespace.
uninstall()
Restore the previous import mechanism.
add_suffix(suffix, importFunc)
Undocumented.
class imputil.Importer
Base class for replacing standard import functions.
import_top(name)
Import a top-level module.
get_code(parent, modname, fqname)
Find and retrieve the code for the given module.
parent specifies a parent module to define a context for importing. It may be None
, indicating no particular context for the search.
modname specifies a single module (not dotted) within the parent.
fqname specifies the fully-qualified module name. This is a (potentially) dotted name from the “root” of the module namespace down to the modname.
If there is no parent, then modname==fqname.
This method should return None
, or a 3-tuple.
None
should be returned.class imputil.BuiltinImporter
Emulate the import mechanism for built-in and frozen modules. This is a sub-class of the Importer
class.
get_code(parent, modname, fqname)
Undocumented.
imputil.py_suffix_importer(filename, finfo, fqname)
Undocumented.
class imputil.DynLoadSuffixImporter([desc])
Undocumented.
import_file(filename, finfo, fqname)
Undocumented.
This is a re-implementation of hierarchical module import.
This code is intended to be read, not executed. However, it does work – all you need to do to enable it is “import knee”.
(The name is a pun on the clunkier predecessor of this module, “ni”.)
import sys, imp, __builtin__ # Replacement for __import__() def import_hook(name, globals=None, locals=None, fromlist=None): parent = determine_parent(globals) q, tail = find_head_package(parent, name) m = load_tail(q, tail) if not fromlist: return q if hasattr(m, "__path__"): ensure_fromlist(m, fromlist) return m def determine_parent(globals): if not globals or not globals.has_key("__name__"): return None pname = globals['__name__'] if globals.has_key("__path__"): parent = sys.modules[pname] assert globals is parent.__dict__ return parent if '.' in pname: i = pname.rfind('.') pname = pname[:i] parent = sys.modules[pname] assert parent.__name__ == pname return parent return None def find_head_package(parent, name): if '.' in name: i = name.find('.') head = name[:i] tail = name[i+1:] else: head = name tail = "" if parent: qname = "%s.%s" % (parent.__name__, head) else: qname = head q = import_module(head, qname, parent) if q: return q, tail if parent: qname = head parent = None q = import_module(head, qname, parent) if q: return q, tail raise ImportError("No module named " + qname) def load_tail(q, tail): m = q while tail: i = tail.find('.') if i < 0: i = len(tail) head, tail = tail[:i], tail[i+1:] mname = "%s.%s" % (m.__name__, head) m = import_module(head, mname, m) if not m: raise ImportError("No module named " + mname) return m def ensure_fromlist(m, fromlist, recursive=0): for sub in fromlist: if sub == "*": if not recursive: try: all = m.__all__ except AttributeError: pass else: ensure_fromlist(m, all, 1) continue if sub != "*" and not hasattr(m, sub): subname = "%s.%s" % (m.__name__, sub) submod = import_module(sub, subname, m) if not submod: raise ImportError("No module named " + subname) def import_module(partname, fqname, parent): try: return sys.modules[fqname] except KeyError: pass try: fp, pathname, stuff = imp.find_module(partname, parent and parent.__path__) except ImportError: return None try: m = imp.load_module(fqname, fp, pathname, stuff) finally: if fp: fp.close() if parent: setattr(parent, partname, m) return m # Replacement for reload() def reload_hook(module): name = module.__name__ if '.' not in name: return import_module(name, name, None) i = name.rfind('.') pname = name[:i] parent = sys.modules[pname] return import_module(name[i+1:], name, parent) # Save the original hooks original_import = __builtin__.__import__ original_reload = __builtin__.reload # Now install our hooks __builtin__.__import__ = import_hook __builtin__.reload = reload_hook
Also see the importers
module (which can be found in Demo/imputil/
in the Python source distribution) for additional examples.
© 2001–2020 Python Software Foundation
Licensed under the PSF License.
https://docs.python.org/2.7/library/imputil.html