I have 20 .csv files which are 2001.csv 2002.csv...... 2020.csv, and I intend to import them into Stata. The following is the command:

forvalues i=2001/2020 {
clear
import delimited 'i'.csv
save 'i'.dta,replace
}

But the command window shows that "i" is invalid. I don't know what the problem is, andI need your advice urgently. Thank you!