Data update

Task/CSV-data-manipulation/Lua/csv-data-manipulation-2.lua

@@ -0,0 +1,26 @@
+local csv={}
+
+-- read csv file, save records and fields into table
+for line in io.lines('file.csv') do
+    local fields = {}
+    for field in line:gmatch"[^,]+" do
+        table.insert(fields, tonumber(field) or field)
+    end
+    table.insert(csv, fields)
+end
+
+-- change csv values
+table.insert(csv[1], 'SUM')
+for i=2,#csv do
+    local sum=0
+    for _, val in ipairs(csv[i]) do
+        sum = sum + val
+    end
+    table.insert(csv[i], sum)
+end
+
+-- Save
+local fileHandler = io.open('file.csv', 'w')
+for NR, fields in ipairs(csv) do
+    fileHandler:write(table.concat(fields,","), "\n")
+end