How to add leading 0 to hexadecimal

Question

The code in the bottom adds hexadecimal numbers to a list in the format:

['0x0', '0x1', ..., '0xa', '0xb', ..., '0xab', ...]

How can I have the single digit hexadecimal numbers have a leading zero, like this:

'0x0' '0x0a'

The code:

K = 256

keys = list(itertools.product([0, 1], repeat=8))
for poss in range(K):
    keys[poss] = hex(int(''.join(map(str, keys[poss])), 2))

Does this answer your question? [Decorating Hex function to pad zeros](https://stackoverflow.com/questions/12638408/decorating-hex-function-to-pad-zeros) — fas, Apr 14 '20 at 11:36
Does this answer your question? [Python , Printing Hex removes first 0?](https://stackoverflow.com/questions/15884677/python-printing-hex-removes-first-0) — hurlenko, Apr 14 '20 at 11:38

score 3 · Answer 1 · answered Apr 14 '20 at 11:34

3

Instead of:

hex(val)

Use:

"0x{:02x}".format(val)

Alternatively, you can use:

"0x%02x" % val

Either of these will give you a zero-padded 2-digit hex value, preceded by 0x.

answered Apr 14 '20 at 11:34

Tom Karzes

1 Answers1