How to convert "str" to "int"

[colt]

Take a look at the struct module.

import struct
four_bytes = b'abcd'  # sample bytesting
struct.unpack("I", four_bytes) # interpret bytesting as unsigned int

From what I see the difference is that you used "I" instead my "h". I changed it and didn't change the error message.

Are you sure it's this line that causes this error message? If 'header' is a bytes string (which you can check by printing the type of the variable) there should be no problem accessing header[4], and it must be an integer. In the worst case it could raise an IndexError.

It says line 11, which is the one that uses struct.unpack. I checked the type and it shows

<class 'bytes'>