The three ratios as Python expressions

Answer

roa = ni / avg_ta roe = (ni - pref_div) / avg_common_equity asset_turnover = revenue / avg_ta

Every denominator is an average of two year-ends. ROE removes preferred dividends from the numerator AND preferred capital from the denominator — both, never one.

Lyryx IFA Vol 2 §22.4.4; Lyryx Intro FA §12.3; Bigel §6.2