I am not sure if you are still watching this thread, but I seem to have
a bit of a problem with the code sample you so graciously provided.
It seems to work in all instances, except the original example I
provided (namely, 1234567890). On my system, the number 1234567890,
gets converted to 1234567895.5.
I made a few changes to your original program, but it is largely the
same with different test samples samples. Any thoughts ??
Sample Code Below ----------------------
# Conversion of Microsoft Binary Format numbers to Python Floats
import binascii as bn
import struct as st
data = [(1234567890,'000000AF052C139F'),
(4069954144,'00000060929672A0'),
(999999.99, '703D0AD7FF237494'),
( 88888.88, '400ad7a3709c2d91'),
( 22222.22, '400ad7a3709c2d8f'),
( 33333.33, 'b047e17a54350290'),
( 1500.34, '7814ae47e18a3b8b'),
( 42345.00, '0000000000692590'),
]
def msd2float(bytes):
if sum(bytes) in [0,72,127]: #take out values that don't make
sense possible the NaN and Infinity ??
return 0.0
b = bytes[:]
sign = bytes[-2]&0x80
b[-2] |= 0x80 #hidden most sig bit in place of sign
exp = bytes[-1] - 0x80 - 56 #exponent offset
acc = 0L
for i,byte in enumerate(b[:-1]):
acc |=(long(byte)<<(i*8))
return (float(acc)*2.0**exp)*((1.,-1.)[sign!=0])
for line in data:
val = line[0]
binval = bn.unhexlify(line[1])
le_bytes = list(st.unpack('BBBBBBBB',binval))
test = msd2float(le_bytes)
print " In:",val, "\nOut:",test,"\n"
Sample Output ------------------------
C:/Python24/pythonw.exe -u "C:/pytest/dms/Test MBF.pyw"
In: 1234567890
Out: 1234567895.5
In: 4069954144
Out: 4069954144.0
In: 999999.99
Out: 999999.99
In: 88888.88
Out: 88888.88
In: 22222.22
Out: 22222.22
In: 33333.33
Out: 33333.33
In: 1500.34
Out: 1500.34
In: 42345.0
Out: 42345.0
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