Reading the first MB of a binary file

[Max Leason]

Hi,

I'm attempting to read the first MB of a binary file and then do a md5
hash on it so that i can find the file later despite it being moved or
any file name changes that may have been made to it. These files are
large (350-1400MB) video files and i often located on a different
computer and I figure that there is a low risk for generating the same
hash between two files. The problem occurs in the read command which
returns all \x00s. Any ideas why this is happening?

Code:
>>>>open("Chuck.S01E01.HDTV.XViD-YesTV.avi", "rb").read(1024)
b'\x00\x00\x00\x00\x00\x00....\x00'