Suppose you have a dataframe that has 2 columns “key” and “value”, and you want to access the value by a corresponding key from your Note, you can use the following notation.
(dataframe name)$value[[(dataframe name)$key=="(key)"]]
For example, if you have a table “kvtable” and key has “blue”, “green”, “red”, you can access values for those keys like the following.