In Sympy, I'm trying to get some symbolic expressions to look exactly like my source material, but it appears that constructors do some rearrangements, most simply Add: >>> a, b = symbols("a b") >>> b+a a + b >>> srepr(b+a) Add(Symbol('a'), Symbol('b')) Obviously this is a good idea most of the time, but I'm trying to show my expressions to be exactly right before doing any change, however obvious. The help for Add says: Add() evaluates the argument unless evaluate=False is passed. The evaluation logic includes: Flattening ... Identity removing ... Coefficient collecting ... Term sorting Add(y, x, 2) -> Add(2, x, y) But it seems not to work: >>> srepr(Add(b, a, evaluate=False)) Add(Symbol('a'), Symbol('b')) Is this possible? Have I missed something? What I'm actually wanting to make is this: ⎛ 1 ⎞ ⎜─────────────────⎟ ⎜ 1 1 ⎟ ⎜─────── + ───────⎟ ⎜R⋅N + S 1 ⎟ ⎜ E + ───⎟ ⎝ s⋅C⎠ ───────────────────────────── ⎛ 1 ⎞ ⎜D + L⋅s + ─────────────────⎟ ⎜ 1 1 ⎟ ⎜ ─────── + ───────⎟ ⎜ R⋅N + S 1 ⎟ ⎜ E + ───⎟ ⎝ s⋅C⎠ But the expression reordering produces the following. 1 ───────────────────────────────────────────────── ⎛ 1 1 ⎞ ⎛ 1 ⎞ ⎜─────── + ───────⎟⋅⎜D + L⋅s + ─────────────────⎟ ⎜N⋅R + S 1 ⎟ ⎜ 1 1 ⎟ ⎜ E + ───⎟ ⎜ ─────── + ───────⎟ ⎝ C⋅s⎠ ⎜ N⋅R + S 1 ⎟ ⎜ E + ───⎟ ⎝ C⋅s⎠ Sympy 1.14.0 Python 3.10.12 Ubuntu 22.04.4 LTS Continue reading...
