cpython-withatomic / Lib / pkgutil.py

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
"""Utilities to support packages."""

import os
import sys
import imp
import os.path
from types import ModuleType

__all__ = [
    'get_importer', 'iter_importers', 'get_loader', 'find_loader',
    'walk_packages', 'iter_modules',
    'ImpImporter', 'ImpLoader', 'read_code', 'extend_path',
]

def read_code(stream):
    # This helper is needed in order for the PEP 302 emulation to
    # correctly handle compiled files
    import marshal

    magic = stream.read(4)
    if magic != imp.get_magic():
        return None

    stream.read(4) # Skip timestamp
    return marshal.load(stream)


def simplegeneric(func):
    """Make a trivial single-dispatch generic function"""
    registry = {}
    def wrapper(*args, **kw):
        ob = args[0]
        try:
            cls = ob.__class__
        except AttributeError:
            cls = type(ob)
        try:
            mro = cls.__mro__
        except AttributeError:
            try:
                class cls(cls, object):
                    pass
                mro = cls.__mro__[1:]
            except TypeError:
                mro = object,   # must be an ExtensionClass or some such  :(
        for t in mro:
            if t in registry:
                return registry[t](*args, **kw)
        else:
            return func(*args, **kw)
    try:
        wrapper.__name__ = func.__name__
    except (TypeError, AttributeError):
        pass    # Python 2.3 doesn't allow functions to be renamed

    def register(typ, func=None):
        if func is None:
            return lambda f: register(typ, f)
        registry[typ] = func
        return func

    wrapper.__dict__ = func.__dict__
    wrapper.__doc__ = func.__doc__
    wrapper.register = register
    return wrapper


def walk_packages(path=None, prefix='', onerror=None):
    """Yields (module_loader, name, ispkg) for all modules recursively
    on path, or, if path is None, all accessible modules.

    'path' should be either None or a list of paths to look for
    modules in.

    'prefix' is a string to output on the front of every module name
    on output.

    Note that this function must import all *packages* (NOT all
    modules!) on the given path, in order to access the __path__
    attribute to find submodules.

    'onerror' is a function which gets called with one argument (the
    name of the package which was being imported) if any exception
    occurs while trying to import a package.  If no onerror function is
    supplied, ImportErrors are caught and ignored, while all other
    exceptions are propagated, terminating the search.

    Examples:

    # list all modules python can access
    walk_packages()

    # list all submodules of ctypes
    walk_packages(ctypes.__path__, ctypes.__name__+'.')
    """

    def seen(p, m={}):
        if p in m:
            return True
        m[p] = True

    for importer, name, ispkg in iter_modules(path, prefix):
        yield importer, name, ispkg

        if ispkg:
            try:
                __import__(name)
            except ImportError:
                if onerror is not None:
                    onerror(name)
            except Exception:
                if onerror is not None:
                    onerror(name)
                else:
                    raise
            else:
                path = getattr(sys.modules[name], '__path__', None) or []

                # don't traverse path items we've seen before
                path = [p for p in path if not seen(p)]

                for item in walk_packages(path, name+'.', onerror):
                    yield item


def iter_modules(path=None, prefix=''):
    """Yields (module_loader, name, ispkg) for all submodules on path,
    or, if path is None, all top-level modules on sys.path.

    'path' should be either None or a list of paths to look for
    modules in.

    'prefix' is a string to output on the front of every module name
    on output.
    """

    if path is None:
        importers = iter_importers()
    else:
        importers = map(get_importer, path)

    yielded = {}
    for i in importers:
        for name, ispkg in iter_importer_modules(i, prefix):
            if name not in yielded:
                yielded[name] = 1
                yield i, name, ispkg


#@simplegeneric
def iter_importer_modules(importer, prefix=''):
    if not hasattr(importer, 'iter_modules'):
        return []
    return importer.iter_modules(prefix)

iter_importer_modules = simplegeneric(iter_importer_modules)


class ImpImporter:
    """PEP 302 Importer that wraps Python's "classic" import algorithm

    ImpImporter(dirname) produces a PEP 302 importer that searches that
    directory.  ImpImporter(None) produces a PEP 302 importer that searches
    the current sys.path, plus any modules that are frozen or built-in.

    Note that ImpImporter does not currently support being used by placement
    on sys.meta_path.
    """

    def __init__(self, path=None):
        self.path = path

    def find_module(self, fullname, path=None):
        # Note: we ignore 'path' argument since it is only used via meta_path
        subname = fullname.split(".")[-1]
        if subname != fullname and self.path is None:
            return None
        if self.path is None:
            path = None
        else:
            path = [os.path.realpath(self.path)]
        try:
            file, filename, etc = imp.find_module(subname, path)
        except ImportError:
            return None
        return ImpLoader(fullname, file, filename, etc)

    def iter_modules(self, prefix=''):
        if self.path is None or not os.path.isdir(self.path):
            return

        yielded = {}
        import inspect

        filenames = os.listdir(self.path)
        filenames.sort()  # handle packages before same-named modules

        for fn in filenames:
            modname = inspect.getmodulename(fn)
            if modname=='__init__' or modname in yielded:
                continue

            path = os.path.join(self.path, fn)
            ispkg = False

            if not modname and os.path.isdir(path) and '.' not in fn:
                modname = fn
                for fn in os.listdir(path):
                    subname = inspect.getmodulename(fn)
                    if subname=='__init__':
                        ispkg = True
                        break
                else:
                    continue    # not a package

            if modname and '.' not in modname:
                yielded[modname] = 1
                yield prefix + modname, ispkg


class ImpLoader:
    """PEP 302 Loader that wraps Python's "classic" import algorithm
    """
    code = source = None

    def __init__(self, fullname, file, filename, etc):
        self.file = file
        self.filename = filename
        self.fullname = fullname
        self.etc = etc

    def load_module(self, fullname):
        self._reopen()
        try:
            mod = imp.load_module(fullname, self.file, self.filename, self.etc)
        finally:
            if self.file:
                self.file.close()
        # Note: we don't set __loader__ because we want the module to look
        # normal; i.e. this is just a wrapper for standard import machinery
        return mod

    def get_data(self, pathname):
        with open(pathname, "rb") as file:
            return file.read()

    def _reopen(self):
        if self.file and self.file.closed:
            mod_type = self.etc[2]
            if mod_type==imp.PY_SOURCE:
                self.file = open(self.filename, 'rU')
            elif mod_type in (imp.PY_COMPILED, imp.C_EXTENSION):
                self.file = open(self.filename, 'rb')

    def _fix_name(self, fullname):
        if fullname is None:
            fullname = self.fullname
        elif fullname != self.fullname:
            raise ImportError("Loader for module %s cannot handle "
                              "module %s" % (self.fullname, fullname))
        return fullname

    def is_package(self, fullname):
        fullname = self._fix_name(fullname)
        return self.etc[2]==imp.PKG_DIRECTORY

    def get_code(self, fullname=None):
        fullname = self._fix_name(fullname)
        if self.code is None:
            mod_type = self.etc[2]
            if mod_type==imp.PY_SOURCE:
                source = self.get_source(fullname)
                self.code = compile(source, self.filename, 'exec')
            elif mod_type==imp.PY_COMPILED:
                self._reopen()
                try:
                    self.code = read_code(self.file)
                finally:
                    self.file.close()
            elif mod_type==imp.PKG_DIRECTORY:
                self.code = self._get_delegate().get_code()
        return self.code

    def get_source(self, fullname=None):
        fullname = self._fix_name(fullname)
        if self.source is None:
            mod_type = self.etc[2]
            if mod_type==imp.PY_SOURCE:
                self._reopen()
                try:
                    self.source = self.file.read()
                finally:
                    self.file.close()
            elif mod_type==imp.PY_COMPILED:
                if os.path.exists(self.filename[:-1]):
                    f = open(self.filename[:-1], 'rU')
                    self.source = f.read()
                    f.close()
            elif mod_type==imp.PKG_DIRECTORY:
                self.source = self._get_delegate().get_source()
        return self.source


    def _get_delegate(self):
        return ImpImporter(self.filename).find_module('__init__')

    def get_filename(self, fullname=None):
        fullname = self._fix_name(fullname)
        mod_type = self.etc[2]
        if self.etc[2]==imp.PKG_DIRECTORY:
            return self._get_delegate().get_filename()
        elif self.etc[2] in (imp.PY_SOURCE, imp.PY_COMPILED, imp.C_EXTENSION):
            return self.filename
        return None


try:
    import zipimport
    from zipimport import zipimporter

    def iter_zipimport_modules(importer, prefix=''):
        dirlist = sorted(zipimport._zip_directory_cache[importer.archive])
        _prefix = importer.prefix
        plen = len(_prefix)
        yielded = {}
        import inspect
        for fn in dirlist:
            if not fn.startswith(_prefix):
                continue

            fn = fn[plen:].split(os.sep)

            if len(fn)==2 and fn[1].startswith('__init__.py'):
                if fn[0] not in yielded:
                    yielded[fn[0]] = 1
                    yield fn[0], True

            if len(fn)!=1:
                continue

            modname = inspect.getmodulename(fn[0])
            if modname=='__init__':
                continue

            if modname and '.' not in modname and modname not in yielded:
                yielded[modname] = 1
                yield prefix + modname, False

    iter_importer_modules.register(zipimporter, iter_zipimport_modules)

except ImportError:
    pass


def get_importer(path_item):
    """Retrieve a PEP 302 importer for the given path item

    The returned importer is cached in sys.path_importer_cache
    if it was newly created by a path hook.

    If there is no importer, a wrapper around the basic import
    machinery is returned. This wrapper is never inserted into
    the importer cache (None is inserted instead).

    The cache (or part of it) can be cleared manually if a
    rescan of sys.path_hooks is necessary.
    """
    try:
        importer = sys.path_importer_cache[path_item]
    except KeyError:
        for path_hook in sys.path_hooks:
            try:
                importer = path_hook(path_item)
                break
            except ImportError:
                pass
        else:
            importer = None
        sys.path_importer_cache.setdefault(path_item, importer)

    if importer is None:
        try:
            importer = ImpImporter(path_item)
        except ImportError:
            importer = None
    return importer


def iter_importers(fullname=""):
    """Yield PEP 302 importers for the given module name

    If fullname contains a '.', the importers will be for the package
    containing fullname, otherwise they will be importers for sys.meta_path,
    sys.path, and Python's "classic" import machinery, in that order.  If
    the named module is in a package, that package is imported as a side
    effect of invoking this function.

    Non PEP 302 mechanisms (e.g. the Windows registry) used by the
    standard import machinery to find files in alternative locations
    are partially supported, but are searched AFTER sys.path. Normally,
    these locations are searched BEFORE sys.path, preventing sys.path
    entries from shadowing them.

    For this to cause a visible difference in behaviour, there must
    be a module or package name that is accessible via both sys.path
    and one of the non PEP 302 file system mechanisms. In this case,
    the emulation will find the former version, while the builtin
    import mechanism will find the latter.

    Items of the following types can be affected by this discrepancy:
        imp.C_EXTENSION, imp.PY_SOURCE, imp.PY_COMPILED, imp.PKG_DIRECTORY
    """
    if fullname.startswith('.'):
        raise ImportError("Relative module names not supported")
    if '.' in fullname:
        # Get the containing package's __path__
        pkg = '.'.join(fullname.split('.')[:-1])
        if pkg not in sys.modules:
            __import__(pkg)
        path = getattr(sys.modules[pkg], '__path__', None) or []
    else:
        for importer in sys.meta_path:
            yield importer
        path = sys.path
    for item in path:
        yield get_importer(item)
    if '.' not in fullname:
        yield ImpImporter()

def get_loader(module_or_name):
    """Get a PEP 302 "loader" object for module_or_name

    If the module or package is accessible via the normal import
    mechanism, a wrapper around the relevant part of that machinery
    is returned.  Returns None if the module cannot be found or imported.
    If the named module is not already imported, its containing package
    (if any) is imported, in order to establish the package __path__.

    This function uses iter_importers(), and is thus subject to the same
    limitations regarding platform-specific special import locations such
    as the Windows registry.
    """
    if module_or_name in sys.modules:
        module_or_name = sys.modules[module_or_name]
    if isinstance(module_or_name, ModuleType):
        module = module_or_name
        loader = getattr(module, '__loader__', None)
        if loader is not None:
            return loader
        fullname = module.__name__
    else:
        fullname = module_or_name
    return find_loader(fullname)

def find_loader(fullname):
    """Find a PEP 302 "loader" object for fullname

    If fullname contains dots, path must be the containing package's __path__.
    Returns None if the module cannot be found or imported. This function uses
    iter_importers(), and is thus subject to the same limitations regarding
    platform-specific special import locations such as the Windows registry.
    """
    for importer in iter_importers(fullname):
        loader = importer.find_module(fullname)
        if loader is not None:
            return loader

    return None


def extend_path(path, name):
    """Extend a package's path.

    Intended use is to place the following code in a package's __init__.py:

        from pkgutil import extend_path
        __path__ = extend_path(__path__, __name__)

    This will add to the package's __path__ all subdirectories of
    directories on sys.path named after the package.  This is useful
    if one wants to distribute different parts of a single logical
    package as multiple directories.

    It also looks for *.pkg files beginning where * matches the name
    argument.  This feature is similar to *.pth files (see site.py),
    except that it doesn't special-case lines starting with 'import'.
    A *.pkg file is trusted at face value: apart from checking for
    duplicates, all entries found in a *.pkg file are added to the
    path, regardless of whether they are exist the filesystem.  (This
    is a feature.)

    If the input path is not a list (as is the case for frozen
    packages) it is returned unchanged.  The input path is not
    modified; an extended copy is returned.  Items are only appended
    to the copy at the end.

    It is assumed that sys.path is a sequence.  Items of sys.path that
    are not (unicode or 8-bit) strings referring to existing
    directories are ignored.  Unicode items of sys.path that cause
    errors when used as filenames may cause this function to raise an
    exception (in line with os.path.isdir() behavior).
    """

    if not isinstance(path, list):
        # This could happen e.g. when this is called from inside a
        # frozen package.  Return the path unchanged in that case.
        return path

    pname = os.path.join(*name.split('.')) # Reconstitute as relative path
    sname_pkg = name + ".pkg"
    init_py = "__init__.py"

    path = path[:] # Start with a copy of the existing path

    for dir in sys.path:
        if not isinstance(dir, str) or not os.path.isdir(dir):
            continue
        subdir = os.path.join(dir, pname)
        # XXX This may still add duplicate entries to path on
        # case-insensitive filesystems
        initfile = os.path.join(subdir, init_py)
        if subdir not in path and os.path.isfile(initfile):
            path.append(subdir)
        # XXX Is this the right thing for subpackages like zope.app?
        # It looks for a file named "zope.app.pkg"
        pkgfile = os.path.join(dir, sname_pkg)
        if os.path.isfile(pkgfile):
            try:
                f = open(pkgfile)
            except IOError as msg:
                sys.stderr.write("Can't open %s: %s\n" %
                                 (pkgfile, msg))
            else:
                for line in f:
                    line = line.rstrip('\n')
                    if not line or line.startswith('#'):
                        continue
                    path.append(line) # Don't check for existence!
                f.close()

    return path

def get_data(package, resource):
    """Get a resource from a package.

    This is a wrapper round the PEP 302 loader get_data API. The package
    argument should be the name of a package, in standard module format
    (foo.bar). The resource argument should be in the form of a relative
    filename, using '/' as the path separator. The parent directory name '..'
    is not allowed, and nor is a rooted name (starting with a '/').

    The function returns a binary string, which is the contents of the
    specified resource.

    For packages located in the filesystem, which have already been imported,
    this is the rough equivalent of

        d = os.path.dirname(sys.modules[package].__file__)
        data = open(os.path.join(d, resource), 'rb').read()

    If the package cannot be located or loaded, or it uses a PEP 302 loader
    which does not support get_data(), then None is returned.
    """

    loader = get_loader(package)
    if loader is None or not hasattr(loader, 'get_data'):
        return None
    mod = sys.modules.get(package) or loader.load_module(package)
    if mod is None or not hasattr(mod, '__file__'):
        return None

    # Modify the resource name to be compatible with the loader.get_data
    # signature - an os.path format "filename" starting with the dirname of
    # the package's __file__
    parts = resource.split('/')
    parts.insert(0, os.path.dirname(mod.__file__))
    resource_name = os.path.join(*parts)
    return loader.get_data(resource_name)
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.