将动态数据转换为数组中的十六进制

Question

I am working on a smartcard in python and using pyscard library. I have the following data:

WRITE_PREF = [0X80, 0X12, 0X00, 0X01, 0X12, 0X01, 0X00, 0X00, 0X20, 0X00, 0X00, 0X00]

I am receiving random data(of length 10) in string format. After conversion to hex, I get the array with hex values of the random string data.

Problem: The array of hex values has the values in string form.

Example: ['0x33','0x32'....]

When I append WRITE_PREF and this hex data, I get the array like this:

[128, 18, 0, 1, 18, 1, 0, 0, 32, 0, 0, 0, '0x33', '0x32']

I convert the first part to hex and replace the array values of integer with the hex ones. When I transmit data using the command:

 card.connection.transmit(final_array_in_hex)

I get error. I am pretty sure it is because the values in array are hex strings. If I transmit some data manually like:

[0x33,0x32,0x30]

It is working fine. So the problem must be because of the quotes in array data. Example:

['0x33','0x32','0x30']

Is there a way to solve this?

Answer 1

You have a str representing a hexadecimal number, let's turn that into an int . We save space using int , also int is flexible. We can choose how to represent this int .

s = ['0x33','0x32']
s = [int(_s, base=16) for _s in s]
print(s) # defaults to displaying an int as decimal
print(list(f'0x{_s:x}' for _s in s)) # specify that we want to display as `x` or hexamdecimal

Output:

[51, 50]
['0x33', '0x32']