python - Python Writing a 512-byte block of zeros to /dev/sda works, but doesn't behave like it is working

Question

Here I am trying to create a function to (eventually) support the wiping of drives using multiple specifications. The problem I am running in to, is when I try to write ZeroBlock to the disk, it gets written, but the code behaves as thou it has failed. the reason i say it worked is that it cleared the boot sector from the drive in my testing system

def WipeDisk(Drive, WipeSpec, Passes):
    DiskSize = int(System.HDD[Drive].Size)
    DiskSect = int(System.HDD[Drive].Sectors())
    SectSize = int(System.HDD[Drive].SectSz)
    System.HDD[Drive].Start = time.time()
    if (WipeSpec == "Zero"):
            with open("/dev/zero", "rb") as Zero:
                    ZeroBlock = Zero.read(SectSize)
            Zero.close()
            Pass = 0
            with open(System.HDD[Drive].Device, "wb") as Disk:
                    while (Pass < Passes):
                            Current = 1
                            while (Current < DiskSect):
                                    if (Disk.write(ZeroBlock)):
                                            if (Current %((DiskSect*Passes)/100) == 0):
                                                    (variable updates)
                                            if (Current == DiskSect):
                                                    Pass = (Pass+1)
                                    else:
                                            System.HDD[Drive].Error = 1
                                            Pass = Passes
                                            break
                                    Current = (Current+1)
                    if (Pass == Passes):
                            System.HDD[Drive].Current = Current
                            System.HDD[Drive].Percent = "100"
                            System.HDD[Drive].Complete = 1
                    Disk.close()
    else:
            print("Unknown Wipe Specification: "+WipeSpec)

Answer 1

The documentation for file.write says:

Write a string to the file. There is no return value.

You appear to be incorrectly assuming that write returns some value indicating whether the write succeeded. It doesn't.