Copy image and split

import os
def main():
 image = pickAFile() #pick the file
 #imgCheck(image)
 fileSize(image)
 # Pick the file and pass it on to the next part

#def imgCheck(image): #check for all image extensions compatible with python
 #here you need to do the checks on whether the file picked is a file compatible with jython
# try:
  #some code here that will throw an exception if an incompatible file is tried, i recommend getHeight(makePicture(image))
# except:
  #show an error message: showInformation("error") etc
# else:
 # fileSize(image)

def fileSize(image): # find the size of the file, dale already gave us this code
 fileStats = os.stat(image)
 fsize = fileStats.st_size
 numberSlices(fsize, image)

def numberSlices(fsize, image): #find the number of slices needed to keep each slice below 20000bytes
 sliceLimit = 20000
 numberSlices = (fsize / sliceLimit) + 1 #add 1 such that uneven divisions will always result in a slice size less than 20000 bytes
 showInformation("Number of Slices:" + str(numberSlices))
 if numberSlices == 1:
  showInformation("This image does not need to be split and can be uploaded")
 else:
  fileExtension(numberSlices, image)

def fileExtension(numberSlices, image):
 #find the file extension and the file path minus the extension
 fileExtension = os.path.splitext(image)[1]
 filePath = os.path.splitext(image)[0]
 splitImage(numberSlices, image, fileExtension, filePath)

def splitImage(numberSlices, image, fileExtension, filePath): #time to split the image, into noSlices many pieces
 pic = makePicture(image)
 imageOrder = 0 #number each file in the order it is saved
 imageHeight = getHeight(pic)
 imageWidth = getWidth(pic)
 imageX = 0 #x pixel coordinate
 imageY = 0 #y pixel coordinate this has to increment
 splitHeight = imageHeight / (numberSlices)
 imgHeight = splitHeight


 for imageOrder in range(0, (numberSlices)):

   canvas = makeEmptyPicture(imageWidth,splitHeight)
   fileName = (filePath + "_" + str(imageOrder) + "_" + str(numberSlices) + fileExtension)
   for sourceX in range(0, imageWidth):
     for sourceY in range(imageY, imgHeight):
       color = getColor(getPixel(pic, sourceX, sourceY))
       setColor(getPixel(canvas, sourceX, sourceY), color)

   writePictureTo(canvas, fileName)

   imageY = imageY + splitHeight
   imgHeight = imgHeight + splitHeight
   imageOrder = imageOrder + 1


 #loop for the last slice starts here this has 2 loops as well.
 #you need to find the height of the last slice in pixels. I used lastHeight = imageHeight - (splitHeight * (numberslices - 1))
 #then specify the fileName again because its a variable
 #canvas = #make the canvas again but this time with the new split height
 #then start the copy function again and make sure you use the right y axis pixels.... think about this.

 #writePictureTo(canvas, fileName)
 print "all done!"