September Morn Update

Task/CSV-data-manipulation/00META.yaml

@@ -0,0 +1 @@
+--- {}

Task/CSV-data-manipulation/Haskell/csv-data-manipulation-1.hs

@@ -1,34 +1,45 @@
-import Data.Array
-import Data.Maybe (isJust)
+import Data.Array (Array(..), (//), bounds, elems, listArray)
 import Data.List (intercalate)
 import Control.Monad (when)
+import Data.Maybe (isJust)
 
+delimiters :: String
 delimiters = ",;:"
 
+fields :: String -> [String]
 fields [] = []
-fields xs = let (item, rest) = break (`elem` delimiters) xs
-                (_,    next) = break (`notElem` delimiters) rest
-    in item : fields next
+fields xs =
+  let (item, rest) = break (`elem` delimiters) xs
+      (_, next) = break (`notElem` delimiters) rest
+  in item : fields next
 
+unfields :: Maybe (Array (Int, Int) String) -> [String]
 unfields Nothing = []
 unfields (Just a) = every fieldNumber $ elems a
-    where
-        ((_, _), (_, fieldNumber)) = bounds a
-        every _ [] = []
-        every n xs = let (y, z) = splitAt n xs
-            in intercalate "," y : every n z
+  where
+    ((_, _), (_, fieldNumber)) = bounds a
+    every _ [] = []
+    every n xs =
+      let (y, z) = splitAt n xs
+      in intercalate "," y : every n z
 
+fieldArray :: [[String]] -> Maybe (Array (Int, Int) String)
 fieldArray [] = Nothing
-fieldArray xs = Just $ listArray ((1,1), (length xs, length $ head xs))
-    $ concat xs
+fieldArray xs =
+  Just $ listArray ((1, 1), (length xs, length $ head xs)) $ concat xs
 
+fieldsFromFile :: FilePath -> IO (Maybe (Array (Int, Int) String))
 fieldsFromFile = fmap (fieldArray . map fields . lines) . readFile
 
+fieldsToFile :: FilePath -> Maybe (Array (Int, Int) String) -> IO ()
 fieldsToFile f = writeFile f . unlines . unfields
 
-someChanges = fmap  (// [((1,1), "changed"), ((3,4), "altered"),
-    ((5,2), "modified")])
+someChanges :: Maybe (Array (Int, Int) String)
+            -> Maybe (Array (Int, Int) String)
+someChanges =
+  fmap (// [((1, 1), "changed"), ((3, 4), "altered"), ((5, 2), "modified")])
 
+main :: IO ()
 main = do
-    a <- fieldsFromFile "example.txt"
-    when (isJust a) $ fieldsToFile "output.txt" $ someChanges a
+  a <- fieldsFromFile "example.txt"
+  when (isJust a) $ fieldsToFile "output.txt" $ someChanges a

Task/CSV-data-manipulation/Objeck/csv-data-manipulation.objeck

@@ -0,0 +1,32 @@
+use System.IO.File;
+use Data.CSV;
+
+class CsvData {
+  function : Main(args : String[]) ~ Nil {
+    file_out : FileWriter;
+    leaving {
+      if(file_out <> Nil) {
+        file_out->Close();
+      };
+    };
+
+    if(args->Size() > 0) {
+      file_name := args[0];
+      csv := CsvTable->New(FileReader->ReadFile(file_name));
+      if(csv->IsParsed()) {
+        csv->AppendColumn("SUM");
+        for(i := 1; i < csv->Size(); i += 1;) {
+          row := csv->Get(i);
+          sum := row->Sum(row->Size() - 1);
+          row->Set("SUM", sum->ToString());
+        };
+      };
+
+      output := csv->ToString();
+      output->PrintLine();
+
+      file_out := FileWriter->New("new-csv.csv");
+      file_out->WriteString(output);
+    };
+  }
+}

Task/CSV-data-manipulation/Python/csv-data-manipulation-2.py

@@ -0,0 +1,22 @@
+import csv
+from pathlib import Path
+from tempfile import NamedTemporaryFile
+
+filepath = Path('data.csv')
+temp_file = NamedTemporaryFile('w',
+                               newline='',
+                               delete=False)
+
+with filepath.open() as csv_file, temp_file:
+    reader = csv.reader(csv_file)
+    writer = csv.writer(temp_file)
+
+    header = next(reader)
+    writer.writerow(header + ['SUM'])
+
+    for row in reader:
+        row_sum = sum(map(int, row))
+        writer.writerow(row + [row_sum])
+
+temp_file_path = Path(temp_file.name)
+temp_file_path.replace(filepath)

Task/CSV-data-manipulation/Python/csv-data-manipulation-3.py

@@ -0,0 +1,8 @@
+import pandas as pd
+
+filepath = 'data.csv'
+
+df = pd.read_csv(filepath)
+rows_sums = df.sum(axis=1)
+df['SUM'] = rows_sums
+df.to_csv(filepath, index=False)

Task/CSV-data-manipulation/Q/csv-data-manipulation.q

@@ -0,0 +1,3 @@
+t:("IIIII";enlist ",")0: `:input.csv    / Read CSV file input.csv into table t
+t:update SUM:sum value flip t from t    / Add SUM column to t
+`:output.csv 0: csv 0: t                / Write updated table as CSV to output.csv

Task/CSV-data-manipulation/REXX/csv-data-manipulation-2.rexx

@@ -0,0 +1,19 @@
+/*REXX program reads a CSV file & appends a SUM column (which is the sum of all columns)*/
+parse arg iFID .                                  /*obtain optional argument from the CL*/
+if iFID=='' | iFID==","  then iFID= 'CSV_SUM.DAT' /*Not specified?  Then use the default*/
+call linein iFID,1,0                              /*position the input file to line one.*/
+                                                  /* [↑]  only needed if pgm is nested. */
+    do rec=1  while lines(iFID)\==0               /*read the input file  (all records). */
+    x= linein(iFid);     y= translate(x, , ',')   /*read a rec; change commas to blanks.*/
+    $= 0                                          /*initial the sum to zero.            */
+                         do j=1  for words(y);     _= word(y, j)    /*get a CSV value.  */
+                         if datatype(_, 'N')  then $= $ + _         /*Numeric? Add to $.*/
+                                              else $= 'SUM'         /*Not? Append "SUM".*/
+                         end   /*j*/
+    @.rec = x','$                                 /*append the   sum   to the record.   */
+    end   /*rec*/                                 /*Note: at EOF,  REC ≡ # of records+1.*/
+say rec-1    ' records read from: '      iFID     /* [↓]  this elides the need for ERASE*/
+call lineout iFID,@.1,1                           /*set file ptr to 1st rec., write hdr.*/
+                         do k=2  for rec-2        /*process all the records just read.  */
+                         call lineout iFID,@.k    /*write the new CSV record (has SUM). */
+                         end   /*k*/              /*stick a fork in it,  we're all done.*/

Task/CSV-data-manipulation/Rust/csv-data-manipulation.rust

@@ -0,0 +1,28 @@
+use std::error::Error;
+use std::num::ParseIntError;
+use csv::{Reader, Writer};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut reader = Reader::from_path("data.csv")?;
+    let mut writer = Writer::from_path("output.csv")?;
+
+    // headers() returns an immutable reference, so clone() before appending
+    let mut headers = reader.headers()?.clone();
+    headers.push_field("SUM");
+    writer.write_record(headers.iter())?;
+
+    for row in reader.records() {
+        let mut row = row?;
+
+        // `sum` needs the type annotation so that `parse::<i64>` knows what error type to return
+        let sum: Result<_, ParseIntError> = row.iter().try_fold(0, |accum, s| {
+            Ok(accum + s.parse::<i64>()?)
+        });
+
+        row.push_field(&sum?.to_string());
+        writer.write_record(row.iter())?;
+    }
+
+    writer.flush()?;
+    Ok(())
+}

Task/CSV-data-manipulation/Stata/csv-data-manipulation.stata

@@ -1,4 +1,5 @@
 import delim input.csv, clear
 replace c5=c3+c4
+egen sum=rowtotal(c*)
 drop if mod(c3,3)==0
 export delim output.csv, replace