in files: frames.append(df)0 1990 58 422 104 NaN MT CO2 Central and South America
1 1995 62 501 125 NaN MT CO2 Eurasia1990 899 777 1026 NaN MT CO2 Central a
显示以A或B开头的国家/地区当我使用以下查询时,它工作正常:when continent in ('europe', 'asia') then 'Eurasia'name like 'B%'select name, case
when continent in ('europe', 'asia') then 'Eurasia
在国家级别绘制地图有许多解决方案,但在我的例子中,我想打印大陆级别的统计数据。## produce the world map## list of countries per continent
SA <- c("argentina", "bolivia", "brazil", "chile", "colombia", "ecuador