I noticed a couple of minor issues and thought I'd post them here rather than making issues on github since the author is reading.

First, desugaring doesn't treat the shebang line of a file properly for executable python scripts on Linux. If the first line is, for example, '#!/usr/bin/env python', then the desugared file has three imports at the top of the file and the shebang line after those imports. It would be nice to preserve the shebang line as the first line (and maybe also to make the desugared file executable if the input file was executable).

Second, the desugaring doesn't ignore commented out lines, as I discovered on commenting out a line like

    #ps.p("my test: " + foo)

before noticing the optional label parameter. Trying to run a file with that line or desugar it results in an IndexError.