> It does not seem to be copying from the training data in any meaningful way.
My point is, I would like to verify this claim with different metrics, because we probably have different interpretations of the word "meaningful".
AlphaCode measures similarity between programs via longest common substrings. That's better than nothing, but that would mean two programs that differ only in variable naming would not be considered similar. If two programs differed only in the names of the variables/functions, I would consider that copying.
I think there are better comparisons of structural similarity: compare the ASTs, or the bytecode/assembly code generated, the control flow graphs, or perform SSA and compare the blocks generated. Each of these might have weaknesses as well, but they won't be as obvious as variable renaming, and so we'd get a better idea of what AlphaCode is copying, and therefore a better idea of its full capabilities.
I expect AlphaCode performs well on Python because the training data is dominated by Python, but Python isn't ideal for comparing program structure. I wonder which programming language (given enough training data) would be best suited for language model generation and analysis.