[Python-ideas] Ideas for improving the struct module

[Elizabeth Myers]

Hello,

I've noticed a lot of binary protocols require variable length
bytestrings (with or without a null terminator), but it is not easy to
unpack these in Python without first reading the desired length, or
reading bytes until a null terminator is reached.

I've noticed the netstruct library
(https://github.com/stendec/netstruct) has a format specifier, $, which
assumes the previous type to pack/unpack is the string's length. This is
an interesting idea in of itself, but doesn't handle the null-terminated
string chase. I know $ is similar to pascal strings, but sometimes you
need more than 255 characters :p.

For null-terminated strings, it may be simpler to have a specifier for
those. I propose 0, but this point can be bikeshedded over endlessly if
desired ;) (I thought about using n/N but they're :P).

It's worth noting that (maybe one of?) Perl's equivalent to the struct
module, whose name escapes me atm, has a module which can handle this
case. I can't remember if it handled variable length or zero-terminated
though; maybe it did both. Perl is more or less my 10th language. :p

This pain point is an annoyance imo and would greatly simplify a lot of
code if implemented, or something like it. I'd be happy to take a look
at implementing it if the idea is received sufficiently warmly.

--
Elizabeth