Code critique please

[kai.peters at gmail.com]

On Tuesday, 7 April 2015 15:43:44 UTC-7, kai.p... at gmail.com  wrote:
> I just wrote this bit (coming from Pascal) and am wondering how seasoned Python programmers would have done the same? Anything terribly non-python?
> 
> As always, thanks for all input.
> 
> K
> 
> 
> 
> """
>  Creates a PNG image from EPD file
> """
> 
> import os, sys
> from PIL import Image, ImageFont, ImageDraw
> 
> # -----------------------------------------------------------------------------
> def RenderByte(draw, byte, x, y):
> 
>     blist = list(bin(byte).lstrip('0b')) # turn byte into list with 8 elements, 
>     c = 0                                # each representing one bit
>     for bit in blist:                   
>         if bit:                
>             draw.point((x + c, y), fcolor)
>             
>         c += 1
>     return
> 
> # -----------------------------------------------------------------------------
> def EPD_2_Image(edpfilename, imagefilename):
>     
>     # get out of here if EPD file not present
>     if not os.path.isfile(epdfilename):
>         print 'file not found: ' + edpfilename
>         return
>     
>     # is this a valid EPD file?
>     filesize = os.path.getsize(epdfilename)
>     if (((xdim / 8) * ydim) + header) <> filesize:
>         print 'incorrect file size: ' + edpfilename
>         return
>     
>     # blow old destination file away 
>     if os.path.isfile(imagefilename):
>         print 'deleting old dest. file: ' + imagefilename
>         os.remove(imagefilename)
> 
>     print 'processing...'
>     
>     # set up PIL objects
>     img  = Image.new('1', (xdim, ydim), bcolor)   # '1' = Bi-tonal image
>     draw = ImageDraw.Draw(img)
>     
>     # read entire EPD file into byte array (without the header)
>     content = bytearray(open(epdfilename, 'rb').read())[16:] 
>      
>     # image coord origin at top/left according to PIL documentation
>     pos = 0
>     for y in range(ydim): 
>         x = 0
>         for byte in range(xdim / 8):   # 8 pixels 'stuffed' into one byte
>             RenderByte(draw, content[pos], x, y)
>             pos += 1           
>             x   += 8
> 
>     img.save(imagefilename)   # format is inferred from given extension
>     print 'done.'
>     
>     return
> # -----------------------------------------------------------------------------
>     
> xdim   = 1024
> ydim   = 1280
> header = 16
> black  = 0
> white  = 1
> bcolor = black
> fcolor = white
> 
> epdfilename   = 'c:\\temp\\drawtest2.epd'
> imagefilename = 'c:\\temp\\drawtest2.png'
> 
> EPD_2_Image(epdfilename, imagefilename)


Thanks for taking the time to give such detailed suggestions - very much appreciated!

K