CODEWITHSUNDEEP
pythonalgorithm
user3262424
user3262424

Reputation: 7479

Python: Creating a Single Integer From Two Integers?

I'm searching for a simple algorithm that 'combines' two 2bytes integers into one unique 4bytes integer.

The two 2bytes integers are both whole positive numbers in the range 0..65535.

I want to create one 4bytes integer that is the exact combination of both, in a way that will make it easy to:

(1) given the two 2bytes integers --> calculate the value of that 4bytes integer.

(2) given the 4bytes integer --> parse the contents of the two 2bytes integers.

Any idea how to achieve this in python?

Upvotes: 3

Views: 557

Answers (2)

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 799150

>>> i1, i2 = 345, 12
>>> i1 * 0x10000 + i2
22609932
>>> divmod(22609932, 0x10000)
(345, 12)

Upvotes: 8

Dirk
Dirk

Reputation: 31061

How about:

def combine(n, m):
    return (n << 16) | m

def extract(c):
    return (c >> 16), c & 0xffff

This solution places one of the 2-byte integers in the upper half of a 32-bit word, and the other into the lower half. In order to extract the values, simply take the upper half of the word (c >> 16), and the lower half (c & 0xffff).

Upvotes: 16

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