"do by sb."是一个表示“对待某人”的英语短语，核心含义是“以某种（好/坏、公平/不公平的）方式对待某人”，尤其强调对待的方式或结果。它是口语化、日常化的表达，常与描述态度的副词（如well, right, wrong, badly等）搭配使用，明确“如何对待”。
"do by sb." = to treat someone in a particular way（以某种方式对待某人）
强调行为的倾向性（比如“善待”“亏待”“公平对待”），比普通的"treat sb."更聚焦“对待的结果或态度”。
通过搭配不同的副词，"do by sb."可以精准表达“如何对待”：
do well by sb.：善待某人；对某人好
do right by sb.：公平对待某人；对得起某人
do wrong by sb.：亏待某人；对某人不公
do badly by sb.：苛待某人；对某人不好
She always does well by her employees—giving them bonuses and flexible hours.
她总是善待员工——给他们奖金和弹性工作时间。
He felt he had done wrong by his family by working too much and missing birthdays.
他觉得自己因工作太多错过生日，亏待了家人。
You should do right by your friends—don’t lie to them.
你应该公平对待朋友——别对他们撒谎。
The company did badly by its workers, cutting their salaries without warning.
公司苛待员工，毫无预警地降薪。
经典谚语：Do by others as you would have them do by you.
（己所不欲，勿施于人；你想别人怎么对待你，就怎么对待别人。）
这里的"do by others"即“对待他人”，"have them do by you"即“让他们对待你”。
口语化：更常用于日常对话，正式写作中可能用"treat sb."替代，但"do by sb."更具情感色彩（比如强调“是否公平”“是否用心”）。
结构：后面直接接“某人”（sb.），不需要额外介词（如do by him，不是do by to him）。
被动语态：可用于被动（be done by sb.），但较少见，比如：She was done well by her boss.（她被老板善待。）
"do by sb."是描述“对待方式”的精准短语，通过搭配副词（well/right/wrong等），可以简洁表达“善待、亏待、公平对待”等态度，是日常交流中常用的表达。