pyasn1 prettyPrint() - display integers in hex

Question

I have many univ.Integer(), but would like to print all of them in hex, which are easy to related to the decoding of substrate.

How can I do it ?

one such example is

namedtype.NamedType('vendor-id', univ.Integer())
namedtype.NamedType('device-id', univ.Integer())
namedtype.NamedType('subven-id', univ.Integer())
namedtype.NamedType('subsys-id', univ.Integer())

any options to pretty print, which will convert all integer to hex ? or subcalss the univ.Integer for some display tricks ?

Answer 1

There is no option to prettyPrint like that. I can offer you two thoughts, though.

If you need to pretty-print specific integers, rather than a tree whole composite objects with embedded Integers, you could just use hex():

>>> Integer(123).prettyPrint()
'123'
>>> hex(int(Integer(123)))
'0x7b'

Otherwise you could amend pyasn1 Integer.prettyOut() method like this:

>>> class MyInteger(Integer):
...     def prettyOut(self, value):
...         return hex(value)
... 
>>> MyInteger(123).prettyPrint()
'0x7b'
>>>