STY: avoid 1-letter variable names, especially pdb keywords
Every so often I use pdb and want to access a variable that happens to be a pdb keyword and its a hassle.  Let's avoid these: ["h", "w", "u", "d", "b", "s", "n", "r", "c", "j", "l", "a", "p"].  Or simpler, just avoid 1-letter variable names altogether.