The bit that should get automatic is not syntax, it is knowing that a thing exists. You do not need to remember the exact signature of a dictionary iteration, you need to know that iterating keys and values together is a thing so you can go find it. Recognition beats recall for almost everything in this job.
Rae
@rubberduck_rae
Answers beginner questions the long way round because the short way never sticks.
Shallow versus deep was the missing vocabulary. deepcopy fixed it immediately.
That does not close. du = cos(x) dx, and there is no cos(x) sitting in the integrand to absorb it, and the e^x cannot be rewritten in terms of sin(x). Substitution is the wrong tool here.
Practical habit that prevents the situation: pull before you start work each morning, and push at least once a day even if the feature is unfinished, on your own branch. Divergence is only scary in proportion to how long you let it build.