  When programmers look for how to achieve certain programming tasks, Stack
Overflow is a popular destination in search engine results. Over the years,
Stack Overflow has accumulated an impressive knowledge base of snippets of code
that are amply documented. We are interested in studying how programmers use
these snippets of code in their projects. Can we find Stack Overflow snippets
in real projects? When snippets are used, is this copy literal or does it
suffer adaptations? And are these adaptations specializations required by the
idiosyncrasies of the target artifact, or are they motivated by specific
requirements of the programmer? The large-scale study presented on this paper
analyzes 909k non-fork Python projects hosted on Github, which contain 290M
function definitions, and 1.9M Python snippets captured in Stack Overflow.
Results are presented as quantitative analysis of block-level code cloning
intra and inter Stack Overflow and GitHub, and as an analysis of programming
behaviors through the qualitative analysis of our findings.
