> aes(x='np.log(B - A)')<p>I never understood the pattern of putting source code in a string. Why not just use np.log(B - A) directly and configure the function to accept columns? With strings you lose highlighting, semantic analysis from editors, as well as the ability to know what computations are happening when and where. There seems to be no point and significant drawback to this, what's the rationale?
Context would be nice, looked through it baffled until I realized this was a port of the Grammar of Graphics to Python to work and look exactly like Hadley's ggplot.<p>I learned R because of my frustrations where Panda's was years ago, seeing this kind of port continues to make me think about moving back to Python from start to finish.