How to read Data from Binary file using python

Question

I want to retrieve the certificate data from smart card. By using SCardTransmit Function from "PyScard" utility we can get the data by sending the apdu's. but the length of the file is so large. Can anyone help me in getting the data in string format and how to get the data. My code in C look like:

    dwLenExpected = ( ( dwOffset + 0xFD ) > dwCertFileSize )?
                                        dwLenExpected : 0xFD;


    Execute the command and get the data copy the data from receive buffer using "memcpy" and increase the offset by length 

    dwOffset += 0xFD;

Now that i want to implement this in python. Any help is appreciated. Thank you in advance