从问题和示例代码看，不清楚你是否希望 df_sub 包含 df1 中的行> 在 df2 中有匹配项，或者没有匹配项.dplyr::semi_join() 将返回匹配的行，dplyr::anti_join() 将返回不匹配的行.

From the question and sample code, it is unclear whether you want df_sub to contain the rows in df1 which do have matches in df2, or the ones without matches. dplyr::semi_join() will return the rows with matches, dplyr::anti_join() will return the rows without matches.

df_sub <- semi_join(x=df1, y=df2, by=c("ID","Weight")) 

或

df_sub <- anti_join(x=df1, y=df2, by=c("ID","Weight"))