Why isn't my re.sub replacing the contents of my MS Word file?

[MRAB]

On 2014-05-13 20:01, scottcabit at gmail.com wrote:
> On Tuesday, May 13, 2014 9:49:12 AM UTC-4, Steven D'Aprano wrote:
>>
>> You may have missed my follow up post, where I said I had not noticed you
>> were operating on a binary .doc file.
>>
>> If you're not willing or able to use a full-blown doc parser, say by
>> controlling Word or LibreOffice, the other alternative is to do something
>> quick and dirty that might work most of the time. Open a doc file, or
>> multiple doc files, in a hex editor and *hopefully* you will be able to
>> see chunks of human-readable text where you can identify how en-dashes
>> and similar are stored.
>
>    I created a .doc file and opened it with UltraEdit in binary (Hex) mode. What I see is that there are two characters, one for ndash and one for mdash, each a single byte long. 0x96 and 0x97.
>    So I tried this: fStr = re.sub(b'\0x96',b'-',fStr)
>
>    that did nothing in my file. So I tried this: fStr = re.sub(b'0x97',b'-',fStr)
>
>    which also did nothing.
>    So, for fun I also tried to just put these wildcards in my re.findall so I added |Part \0x96|Part \0x97    to no avail.
>
>    Obviously 0x96 and 0x97 are NOT being interpreted in a re.findall or re.sub as hex byte values of 96 and 97 hexadecimal using my current syntax.
>
>    So here's my question...if I want to replace all ndash  or mdash values with regular '-' symbols using re.sub, what is the proper syntax to do so?
>
>    Thanks!
>
0x96 is a hexadecimal literal for an int. Within a string you need \x96
(it's \x for 2 hex digits, \u for 4 hex digits, \U for 8 hex digits).