How to efficiently write System.Array to a binary file in IronPython?

Question

I have to write a System.Array (1e09 items from type Single) to a binary file. I could of course loop over the Array with .GetValue() and pack each Single in a 4-Byte struct, but this is very slow.

Is it possible to use the standard Python file i/o in this case? I have tried somefile_write(some_systemarray) , but this results in an error message.

I am mainly interested in 1D arrays, however an answer which works for nD arrays would be highly appreciated.

Edit After reading the first comment, I have tried the following code:

    from System import *
    from System.IO import *

    arr = Array.CreateInstance(Single, 1e8)
    b = BinaryWriter(File.Open('test.bin', FileMode.Create))
    for i in arr :
       b.Write(i)
    b.Close()

Unfortunately, this takes appr. 45 sec. There is BinaryWriter.Write(Byte[]) available. However, this will only speed up things when it is possible to convert System.Array to Byte[] quickly.

Answer 1

Have you tried creating an array of Byte instead of an array of Single?

from System import *
from System.IO import *

arr = Array.CreateInstance(Byte, 1e8)
b = BinaryWriter(File.Open('test.bin', FileMode.Create))
b.Write(arr)
b.Close()