Random 32 hexadecimal digits in Python

Question

I am trying to find a great way to produce a 32 digit hex sequence that is random and gets its randomness from a Big Number like 10*78.

For Python code I also found this:

ran = random.randrange(10**80)
myhex = "%030x" % ran

This produces a 64 digit hex string, BUT sometimes the result is 63 or even 61 characters and I'm not sure why? I need it to return 64 exactly each time.

I need helping tweaking the above code so that it ALWAYS returns 64 only. I do not know enough about the how the "%030x" part works.

I've also tried producing a longer hex string and shortening it with:

myhex = myhex[:64]

But I was still seeing strings that were less than 64 being returned.

In the end I just need exactly 64 hexadecimal string derived from a Big Number like 10*78, returned each time.

Solution I went with

import random

ran = random.randrange(10**80)
myhex = "%064x" % ran

#limit string to 64 characters
myhex = myhex[:64]

print(myhex)

Seems @ScottMillers answer below was the key I needed to find the answer so I'm selecting his answer as the solution, but wanted to post my final code that worked for me here.

Thanks everyone

Answer 1

In modern Python distributions, the new library secrets makes it easy and might be what you need. From the docs:

The secrets module is used for generating cryptographically strong random numbers suitable for managing data such as passwords, account authentication, security tokens, and related secrets.

In particularly, secrets should be used in preference to the default pseudo-random number generator in the random module, which is designed for modeling and simulation, not security or cryptography.

For Python 3.6 and up, try this:

import secrets
secrets.token_hex(32)
#'17450056b398cbeda1fa7e4fc25d4fb169ade2b1266892e2cecab56b12fb900b'

https://docs.python.org/3/library/secrets.html#module-secrets

For earlier versions of Python, there is a backport available (python2-secrets).

   pip install python2-secrets

Answer 2

The UUID module can return a 32 hexadecimal digits object:

import uuid
uuid.uuid4().hex
# '7dccf8a43a6c4e018caadacdb2d0f6f0'