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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def rename_files(files, name=None):
 """ Given a list of file paths for elevation files, this function will rename those files to the format required by the pyDEM package. This assumes a .tif extension. Parameters files : list A list of strings of the paths to the elevation files that will be renamed name : str (optional) Default = None. A suffix to the filename. For example <filename>_suffix.tif Notes ------ The files are renamed in the same directory as the original file locations """

    for fil in files:
        elev_file = GdalReader(file_name=fil)
        elev, = elev_file.raster_layers
        fn = get_fn(elev, name)
        del elev_file
        del elev
        fn = os.path.join(os.path.split(fil)[0], fn)
        os.rename(fil, fn)
        print "Renamed", fil, "to", fn