How to remove some bytes from a byte string?-CodePudding

I am trying to remove a byte (\x00\x81) from a byte string sByte.

sByte = b'\x00\x81308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'

I am expecting to have as a result the following:

sByte = b'308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'

I have tried the following:

I tried to decode sByte; after running the below line of code,
```
sByte.decode('utf-8')
```
I received a traceback: UnicodeDecodeError: 'utf-8' codec can't decode byte 0x81 in position 1: invalid start byte.
I also tried the following, but did not work:
```
sByte.replace('\x00\x81', '')
```
I also found this:
json - UnicodeDecodeError: 'utf8' codec can't decode byte 0x80 in position 3131: invalid start byte) but it did not help removing \x00\x81.

I am not sure how we can remove or replace a byte in byte string.

CodePudding user response：

bytes.replace doesn't work in-place, it returns a modified copy of the bytes object. You can use sByte = sByte.replace(b'\x00\x81', b'') (or bytes.removeprefix if the bytes always occur at the start). Depending on your circumstances, you can also set the errors parameter of the decode method to 'ignore': sByte = sByte.decode(encoding='utf-8', errors='ignore').

CodePudding user response：

>>> sByte = b'\x00\x81308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'
>>> sByte[2:]
b'308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'

The code snippet returns sByte from and including the third byte until the end.

If you wanted to store the variable again you could do this:

>>> sByte = b'\x00\x81308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'
>>> sByte = sByte[2:]
>>> sByte
b'308 921 q53 246 133 137 022 1   0 1 1  1 130 C13 330 0000000199 04002201\n'