OleFileIO_PL 0.30

About the structure of OLE files

An OLE file can be seen as a mini file system or a Zip archive: It contains streams of data that look like files embedded within the OLE file. Each stream has a name. For example, the main stream of a MS Word document containing its text is named “WordDocument”.

An OLE file can also contain storages. A storage is a folder that contains streams or other storages. For example, a MS Word document with VBA macros has a storage called “Macros”.

Special streams can contain properties. A property is a specific value that can be used to store information such as the metadata of a document (title, author, creation date, etc). Property stream names usually start with the character ‘05’.

For example, a typical MS Word document may look like this:

'\x05DocumentSummaryInformation' (stream)
'\x05SummaryInformation' (stream)
'WordDocument' (stream)
'Macros' (storage)
    'PROJECT' (stream)
    'PROJECTwm' (stream)
    'VBA' (storage)
        'Module1' (stream)
        'ThisDocument' (stream)
        '_VBA_PROJECT' (stream)
        'dir' (stream)
'ObjectPool' (storage)

Import OleFileIO_PL

import OleFileIO_PL

As of version 0.30, the code has been changed to be compatible with Python 3.x. As a consequence, compatibility with Python 2.5 or older is not provided anymore. However, a copy of v0.26 is available as OleFileIO_PL2.py. If your application needs to be compatible with Python 2.5 or older, you may use the following code to load the old version when needed:

try:
    import OleFileIO_PL
except:
    import OleFileIO_PL2 as OleFileIO_PL

If you think OleFileIO_PL should stay compatible with Python 2.5 or older, please contact me.

Test if a file is an OLE container

Use isOleFile to check if the first bytes of the file contain the Magic for OLE files, before opening it. isOleFile returns True if it is an OLE file, False otherwise.

assert OleFileIO_PL.isOleFile('myfile.doc')

Open an OLE file from disk

Create an OleFileIO object with the file path as parameter:

ole = OleFileIO_PL.OleFileIO('myfile.doc')

Open an OLE file from a file-like object

This is useful if the file is not on disk, e.g. already stored in a string or as a file-like object.

ole = OleFileIO_PL.OleFileIO(f)

For example the code below reads a file into a string, then uses BytesIO to turn it into a file-like object.

data = open('myfile.doc', 'rb').read()
f = io.BytesIO(data) # or StringIO.StringIO for Python 2.x
ole = OleFileIO_PL.OleFileIO(f)

How to handle malformed OLE files

By default, the parser is configured to be as robust and permissive as possible, allowing to parse most malformed OLE files. Only fatal errors will raise an exception. It is possible to tell the parser to be more strict in order to raise exceptions for files that do not fully conform to the OLE specifications, using the raise_defect option (new in v0.14):

ole = OleFileIO_PL.OleFileIO('myfile.doc', raise_defects=DEFECT_INCORRECT)

When the parsing is done, the list of non-fatal issues detected is available as a list in the parsing_issues attribute of the OleFileIO object (new in 0.25):

print('Non-fatal issues raised during parsing:')
if ole.parsing_issues:
    for exctype, msg in ole.parsing_issues:
        print('- %s: %s' % (exctype.__name__, msg))
else:
    print('None')

Syntax for stream and storage path

Two different syntaxes are allowed for methods that need or return the path of streams and storages:

1. Either a list of strings including all the storages from the root up to the stream/storage name. For example a stream called “WordDocument” at the root will have [‘WordDocument’] as full path. A stream called “ThisDocument” located in the storage “Macros/VBA” will be [‘Macros’, ‘VBA’, ‘ThisDocument’]. This is the original syntax from PIL. While hard to read and not very convenient, this syntax works in all cases.

2. Or a single string with slashes to separate storage and stream names (similar to the Unix path syntax). The previous examples would be ‘WordDocument’ and ‘Macros/VBA/ThisDocument’. This syntax is easier, but may fail if a stream or storage name contains a slash. (new in v0.15)

Both are case-insensitive.

Switching between the two is easy:

slash_path = '/'.join(list_path)
list_path  = slash_path.split('/')

Get the list of streams

listdir() returns a list of all the streams contained in the OLE file, including those stored in storages. Each stream is listed itself as a list, as described above.

print(ole.listdir())

Sample result:

[['\x01CompObj'], ['\x05DocumentSummaryInformation'], ['\x05SummaryInformation']
, ['1Table'], ['Macros', 'PROJECT'], ['Macros', 'PROJECTwm'], ['Macros', 'VBA',
'Module1'], ['Macros', 'VBA', 'ThisDocument'], ['Macros', 'VBA', '_VBA_PROJECT']
, ['Macros', 'VBA', 'dir'], ['ObjectPool'], ['WordDocument']]

As an option it is possible to choose if storages should also be listed, with or without streams (new in v0.26):

ole.listdir (streams=False, storages=True)

Test if known streams/storages exist:

exists(path) checks if a given stream or storage exists in the OLE file.

if ole.exists('worddocument'):
    print("This is a Word document.")
    if ole.exists('macros/vba'):
         print("This document seems to contain VBA macros.")

Read data from a stream

openstream(path) opens a stream as a file-like object.

The following example extracts the “Pictures” stream from a PPT file:

pics = ole.openstream('Pictures')
data = pics.read()

Get information about a stream/storage

Several methods can provide the size, type and timestamps of a given stream/storage:

get_size(path) returns the size of a stream in bytes:

s = ole.get_size('WordDocument')

get_type(path) returns the type of a stream/storage, as one of the following constants: STGTY_STREAM for a stream, STGTY_STORAGE for a storage, STGTY_ROOT for the root entry, and False for a non existing path.

t = ole.get_type('WordDocument')

get_ctime(path) and get_mtime(path) return the creation and modification timestamps of a stream/storage, as a Python datetime object with UTC timezone. Please note that these timestamps are only present if the application that created the OLE file explicitly stored them, which is rarely the case. When not present, these methods return None.

c = ole.get_ctime('WordDocument')
m = ole.get_mtime('WordDocument')

Extract metadata

get_metadata() will check if standard property streams exist, parse all the properties they contain, and return an OleMetadata object with the found properties as attributes (new in v0.24).

meta = ole.get_metadata()
print('Author:', meta.author)
print('Title:', meta.title)
print('Creation date:', meta.create_time)
# print all metadata:
meta.dump()

Available attributes include:

codepage, title, subject, author, keywords, comments, template,
last_saved_by, revision_number, total_edit_time, last_printed, create_time,
last_saved_time, num_pages, num_words, num_chars, thumbnail,
creating_application, security, codepage_doc, category, presentation_target,
bytes, lines, paragraphs, slides, notes, hidden_slides, mm_clips,
scale_crop, heading_pairs, titles_of_parts, manager, company, links_dirty,
chars_with_spaces, unused, shared_doc, link_base, hlinks, hlinks_changed,
version, dig_sig, content_type, content_status, language, doc_version

See the source code of the OleMetadata class for more information.

Parse a property stream

get_properties(path) can be used to parse any property stream that is not handled by get_metadata. It returns a dictionary indexed by integers. Each integer is the index of the property, pointing to its value. For example in the standard property stream ‘05SummaryInformation’, the document title is property #2, and the subject is #3.

p = ole.getproperties('specialprops')

By default as in the original PIL version, timestamp properties are converted into a number of seconds since Jan 1,1601. With the option convert_time, you can obtain more convenient Python datetime objects (UTC timezone). If some time properties should not be converted (such as total editing time in ‘05SummaryInformation’), the list of indexes can be passed as no_conversion (new in v0.25):

p = ole.getproperties('specialprops', convert_time=True, no_conversion=[10])

Close the OLE file

Unless your application is a simple script that terminates after processing an OLE file, do not forget to close each OleFileIO object after parsing to close the file on disk. (new in v0.22)

ole.close()

Use OleFileIO_PL as a script

OleFileIO_PL can also be used as a script from the command-line to display the structure of an OLE file and its metadata, for example:

OleFileIO_PL.py myfile.doc