PCQRSCANER/venv/Lib/site-packages/pptx/opc/phys_pkg.py

160 lines
4.2 KiB
Python
Raw Normal View History

2019-12-22 21:51:47 +01:00
# encoding: utf-8
"""
Provides a general interface to a *physical* OPC package, such as a zip file.
"""
from __future__ import absolute_import
import os
from zipfile import ZipFile, is_zipfile, ZIP_DEFLATED
from ..compat import is_string
from ..exceptions import PackageNotFoundError
from .packuri import CONTENT_TYPES_URI
class PhysPkgReader(object):
"""
Factory for physical package reader objects.
"""
def __new__(cls, pkg_file):
# if *pkg_file* is a string, treat it as a path
if is_string(pkg_file):
if os.path.isdir(pkg_file):
reader_cls = _DirPkgReader
elif is_zipfile(pkg_file):
reader_cls = _ZipPkgReader
else:
raise PackageNotFoundError("Package not found at '%s'" % pkg_file)
else: # assume it's a stream and pass it to Zip reader to sort out
reader_cls = _ZipPkgReader
return super(PhysPkgReader, cls).__new__(reader_cls)
class PhysPkgWriter(object):
"""
Factory for physical package writer objects.
"""
def __new__(cls, pkg_file):
return super(PhysPkgWriter, cls).__new__(_ZipPkgWriter)
class _DirPkgReader(PhysPkgReader):
"""
Implements |PhysPkgReader| interface for an OPC package extracted into a
directory.
"""
def __init__(self, path):
"""
*path* is the path to a directory containing an expanded package.
"""
super(_DirPkgReader, self).__init__()
self._path = os.path.abspath(path)
def blob_for(self, pack_uri):
"""
Return contents of file corresponding to *pack_uri* in package
directory.
"""
path = os.path.join(self._path, pack_uri.membername)
with open(path, "rb") as f:
blob = f.read()
return blob
def close(self):
"""
Provides interface consistency with |ZipFileSystem|, but does
nothing, a directory file system doesn't need closing.
"""
pass
@property
def content_types_xml(self):
"""
Return the `[Content_Types].xml` blob from the package.
"""
return self.blob_for(CONTENT_TYPES_URI)
def rels_xml_for(self, source_uri):
"""
Return rels item XML for source with *source_uri*, or None if the
item has no rels item.
"""
try:
rels_xml = self.blob_for(source_uri.rels_uri)
except IOError:
rels_xml = None
return rels_xml
class _ZipPkgReader(PhysPkgReader):
"""
Implements |PhysPkgReader| interface for a zip file OPC package.
"""
def __init__(self, pkg_file):
super(_ZipPkgReader, self).__init__()
self._zipf = ZipFile(pkg_file, "r")
def blob_for(self, pack_uri):
"""
Return blob corresponding to *pack_uri*. Raises |ValueError| if no
matching member is present in zip archive.
"""
return self._zipf.read(pack_uri.membername)
def close(self):
"""
Close the zip archive, releasing any resources it is using.
"""
self._zipf.close()
@property
def content_types_xml(self):
"""
Return the `[Content_Types].xml` blob from the zip package.
"""
return self.blob_for(CONTENT_TYPES_URI)
def rels_xml_for(self, source_uri):
"""
Return rels item XML for source with *source_uri* or None if no rels
item is present.
"""
try:
rels_xml = self.blob_for(source_uri.rels_uri)
except KeyError:
rels_xml = None
return rels_xml
class _ZipPkgWriter(PhysPkgWriter):
"""
Implements |PhysPkgWriter| interface for a zip file OPC package.
"""
def __init__(self, pkg_file):
super(_ZipPkgWriter, self).__init__()
self._zipf = ZipFile(pkg_file, "w", compression=ZIP_DEFLATED)
def close(self):
"""
Close the zip archive, flushing any pending physical writes and
releasing any resources it's using.
"""
self._zipf.close()
def write(self, pack_uri, blob):
"""
Write *blob* to this zip package with the membername corresponding to
*pack_uri*.
"""
self._zipf.writestr(pack_uri.membername, blob)