Viewing file:  zipp.py (8.23 KB) -rw-r--r--
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import io
import posixpath
import zipfile
import itertools
import contextlib
import sys
import pathlib
if sys.version_info < (3, 7):
from collections import OrderedDict
else:
OrderedDict = dict
__all__ = ['Path']
def _parents(path):
"""
Given a path with elements separated by
posixpath.sep, generate all parents of that path.
>>> list(_parents('b/d'))
['b']
>>> list(_parents('/b/d/'))
['/b']
>>> list(_parents('b/d/f/'))
['b/d', 'b']
>>> list(_parents('b'))
[]
>>> list(_parents(''))
[]
"""
return itertools.islice(_ancestry(path), 1, None)
def _ancestry(path):
"""
Given a path with elements separated by
posixpath.sep, generate all elements of that path
>>> list(_ancestry('b/d'))
['b/d', 'b']
>>> list(_ancestry('/b/d/'))
['/b/d', '/b']
>>> list(_ancestry('b/d/f/'))
['b/d/f', 'b/d', 'b']
>>> list(_ancestry('b'))
['b']
>>> list(_ancestry(''))
[]
"""
path = path.rstrip(posixpath.sep)
while path and path != posixpath.sep:
yield path
path, tail = posixpath.split(path)
_dedupe = OrderedDict.fromkeys
"""Deduplicate an iterable in original order"""
def _difference(minuend, subtrahend):
"""
Return items in minuend not in subtrahend, retaining order
with O(1) lookup.
"""
return itertools.filterfalse(set(subtrahend).__contains__, minuend)
class CompleteDirs(zipfile.ZipFile):
"""
A ZipFile subclass that ensures that implied directories
are always included in the namelist.
"""
@staticmethod
def _implied_dirs(names):
parents = itertools.chain.from_iterable(map(_parents, names))
as_dirs = (p + posixpath.sep for p in parents)
return _dedupe(_difference(as_dirs, names))
def namelist(self):
names = super(CompleteDirs, self).namelist()
return names + list(self._implied_dirs(names))
def _name_set(self):
return set(self.namelist())
def resolve_dir(self, name):
"""
If the name represents a directory, return that name
as a directory (with the trailing slash).
"""
names = self._name_set()
dirname = name + '/'
dir_match = name not in names and dirname in names
return dirname if dir_match else name
@classmethod
def make(cls, source):
"""
Given a source (filename or zipfile), return an
appropriate CompleteDirs subclass.
"""
if isinstance(source, CompleteDirs):
return source
if not isinstance(source, zipfile.ZipFile):
return cls(_pathlib_compat(source))
# Only allow for FastLookup when supplied zipfile is read-only
if 'r' not in source.mode:
cls = CompleteDirs
source.__class__ = cls
return source
class FastLookup(CompleteDirs):
"""
ZipFile subclass to ensure implicit
dirs exist and are resolved rapidly.
"""
def namelist(self):
with contextlib.suppress(AttributeError):
return self.__names
self.__names = super(FastLookup, self).namelist()
return self.__names
def _name_set(self):
with contextlib.suppress(AttributeError):
return self.__lookup
self.__lookup = super(FastLookup, self)._name_set()
return self.__lookup
def _pathlib_compat(path):
"""
For path-like objects, convert to a filename for compatibility
on Python 3.6.1 and earlier.
"""
try:
return path.__fspath__()
except AttributeError:
return str(path)
class Path:
"""
A pathlib-compatible interface for zip files.
Consider a zip file with this structure::
.
├── a.txt
└── b
├── c.txt
└── d
└── e.txt
>>> data = io.BytesIO()
>>> zf = zipfile.ZipFile(data, 'w')
>>> zf.writestr('a.txt', 'content of a')
>>> zf.writestr('b/c.txt', 'content of c')
>>> zf.writestr('b/d/e.txt', 'content of e')
>>> zf.filename = 'mem/abcde.zip'
Path accepts the zipfile object itself or a filename
>>> root = Path(zf)
From there, several path operations are available.
Directory iteration (including the zip file itself):
>>> a, b = root.iterdir()
>>> a
Path('mem/abcde.zip', 'a.txt')
>>> b
Path('mem/abcde.zip', 'b/')
name property:
>>> b.name
'b'
join with divide operator:
>>> c = b / 'c.txt'
>>> c
Path('mem/abcde.zip', 'b/c.txt')
>>> c.name
'c.txt'
Read text:
>>> c.read_text()
'content of c'
existence:
>>> c.exists()
True
>>> (b / 'missing.txt').exists()
False
Coercion to string:
>>> import os
>>> str(c).replace(os.sep, posixpath.sep)
'mem/abcde.zip/b/c.txt'
At the root, ``name``, ``filename``, and ``parent``
resolve to the zipfile. Note these attributes are not
valid and will raise a ``ValueError`` if the zipfile
has no filename.
>>> root.name
'abcde.zip'
>>> str(root.filename).replace(os.sep, posixpath.sep)
'mem/abcde.zip'
>>> str(root.parent)
'mem'
"""
__repr = "{self.__class__.__name__}({self.root.filename!r}, {self.at!r})"
def __init__(self, root, at=""):
"""
Construct a Path from a ZipFile or filename.
Note: When the source is an existing ZipFile object,
its type (__class__) will be mutated to a
specialized type. If the caller wishes to retain the
original type, the caller should either create a
separate ZipFile object or pass a filename.
"""
self.root = FastLookup.make(root)
self.at = at
def open(self, mode='r', *args, pwd=None, **kwargs):
"""
Open this entry as text or binary following the semantics
of ``pathlib.Path.open()`` by passing arguments through
to io.TextIOWrapper().
"""
if self.is_dir():
raise IsADirectoryError(self)
zip_mode = mode[0]
if not self.exists() and zip_mode == 'r':
raise FileNotFoundError(self)
stream = self.root.open(self.at, zip_mode, pwd=pwd)
if 'b' in mode:
if args or kwargs:
raise ValueError("encoding args invalid for binary operation")
return stream
return io.TextIOWrapper(stream, *args, **kwargs)
@property
def name(self):
return pathlib.Path(self.at).name or self.filename.name
@property
def suffix(self):
return pathlib.Path(self.at).suffix or self.filename.suffix
@property
def suffixes(self):
return pathlib.Path(self.at).suffixes or self.filename.suffixes
@property
def stem(self):
return pathlib.Path(self.at).stem or self.filename.stem
@property
def filename(self):
return pathlib.Path(self.root.filename).joinpath(self.at)
def read_text(self, *args, **kwargs):
with self.open('r', *args, **kwargs) as strm:
return strm.read()
def read_bytes(self):
with self.open('rb') as strm:
return strm.read()
def _is_child(self, path):
return posixpath.dirname(path.at.rstrip("/")) == self.at.rstrip("/")
def _next(self, at):
return self.__class__(self.root, at)
def is_dir(self):
return not self.at or self.at.endswith("/")
def is_file(self):
return self.exists() and not self.is_dir()
def exists(self):
return self.at in self.root._name_set()
def iterdir(self):
if not self.is_dir():
raise ValueError("Can't listdir a file")
subs = map(self._next, self.root.namelist())
return filter(self._is_child, subs)
def __str__(self):
return posixpath.join(self.root.filename, self.at)
def __repr__(self):
return self.__repr.format(self=self)
def joinpath(self, *other):
next = posixpath.join(self.at, *map(_pathlib_compat, other))
return self._next(self.root.resolve_dir(next))
__truediv__ = joinpath
@property
def parent(self):
if not self.at:
return self.filename.parent
parent_at = posixpath.dirname(self.at.rstrip('/'))
if parent_at:
parent_at += '/'
return self._next(parent_at)
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