Individual process for decompression

def decompressBWTPoolProcess(tup):
    '''
    Individual process for decompression
    '''
    (inputDir, outputDir, startIndex, endIndex) = tup
    
    if startIndex == endIndex:
        return True
    
    #load the thing we'll be extracting from
    msbwt = MultiStringBWT.CompressedMSBWT()
    msbwt.loadMsbwt(inputDir, None)
    
    #open our output
    outputBwt = np.load(outputDir+'/msbwt.npy', 'r+')
    outputBwt[startIndex:endIndex] = msbwt.getBWTRange(startIndex, endIndex)   
    
    return True