Convert priv key to compressed public key

[PietCoin97]

this is my first pub key

Code:

0489158b199bec930e2d10f0c16e214571c0c17287f0ee93193ca385b79135db3faab396827dea71071568548e9ddc0ffdefe649db9b8601e3db79a8d1e91c0797

and output is

03    4   89158b199bec930e2d10f0c16e214571c0c17287f0ee93193ca385b79135db3f

and the 4 is too much

[1715604000]

1715604000

[1715604000]

1715604000

[jackg]

I have it!

As per what pooya said:
1. take the uncompressed public key and drop its first byte (which is 0x04)
2. split the remaining 64 bytes into 2x 32 bytes
3. take the first 32 byte, this is your (x coordinate) compressed public key after next step
4. take the second 32 bytes (y coordinate) if it was even add 0x02 otherwise 0x03 to the beginning of step 3

Code:

f = open(“keys.txt”,”r”)
even = ["0","2","4","6","8","A","C","E","a","c","e"]
for line in f:
    public_key_u=line
    public_key_x,public_key_y = public_key_u[2:67],public_key_u[67:132]
    if public_key_y[len(public_key_y)-1] in even:
        hex_compressed_public_key = "02"+public_key_x
    else:
        hex_compressed_public_key = "03"+public_key_x
    x = open(“compressedkeys.txt”,”a”)
    x.write(hex_compressed_public_key +”\n”)
    x.close()

I'm expecting the public keys to be in hex

I'm hoping my maths isn't off too.

Run the new code. I changed line 5.

[Coding Enthusiast]

change:
public_key_x,public_key_y = public_key_u[1:66],public_key_u[66:130]
to
public_key_x,public_key_y = public_key_u[2:66],public_key_u[66:130]

[PietCoin97]

yeah it is

public_key_x,public_key_y = public_key_u[1:66],public_key_u[66:130]
to
public_key_x,public_key_y = public_key_u[2:66],public_key_u[66:130]

[jackg]

change:
public_key_x,public_key_y = public_key_u[1:66],public_key_u[66:130]
to
public_key_x,public_key_y = public_key_u[2:66],public_key_u[66:130]

Well that went badly . Probably better than expected actually, I've been doing too much with signatures clearly . Simple maths definitely isn't the strong point.

[PietCoin97]

No problem thank you very much for your help guys.