import os

filename = "sparse"

data = b'x' * 4096
offsets = ( 4096, 12288, 20480, 28672, 36864, 45056, 53248, 61440, 69632,
        77824,)

with open(filename, "wb") as fp:
    for offset in offsets:
        fp.seek(offset)
        fp.write(data)

    fp.seek(86016)
    fp.write(b'')

    fp.seek(86016)
    fp.truncate()

st = os.stat(filename)
a = st.st_blocks * 512
b = st.st_size
if a < b:
    print("succeeded to created a sparse file:"
          " %r (st_blocks * 512) < %r (st_size)" % (a, b))
else:
    print("FAILED to created a sparse file: "
          "%r (st_blocks * 512) >= %r (st_size)" % (a, b))

#os.unlink(filename)