Go VS Python, silly but real metrics

main.go

package main

func main() {
	for i := 0; i < N; i++ {

	}
}

main.py

def main():
    for _ in range(int(N)):
        pass


if __name__ == "__main__":
    main()

parse_time.go

package main

// Parse the timings-only file, big_loops.txt from run.sh, and print CSV.

import (
	"bufio"
	"encoding/csv"
	"log"
	"os"
	"strings"
)

func main() {
	fname := os.Args[1]

	f, err := os.Open(fname)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	records := [][]string{
		{"Magnitude_N", "Prog", "User_s", "System_s", "CPU_%", "Total_s"},
	}

	r := bufio.NewScanner(f)
	for r.Scan() {
		line := r.Text()

		var split []string
		var rem string
		var mag_n, prog, user, system, cpu, total string

		// Start "popping" text off the front of the line...

		split = strings.SplitN(line, " ", 2)
		mag_n = split[0]
		rem = split[1]

		split = strings.SplitN(rem, "  ", 2) // double space separates cmd and timings
		prog = split[0]
		rem = split[1]

		split = strings.SplitN(rem, " user ", 2)
		user = split[0]
		rem = split[1]

		split = strings.SplitN(rem, " system ", 2)
		system = split[0]
		rem = split[1]

		split = strings.SplitN(rem, " cpu ", 2)
		cpu = split[0]
		rem = split[1]

		split = strings.SplitN(rem, " total", 2)
		total = split[0]
		rem = split[1]

		// Get rid of unwanted symbols, and some junk in the program name
		mag_n = rmv(mag_n, "s")
		user = rmv(user, "s")
		system = rmv(system, "s")
		cpu = rmv(cpu, "%")
		total = rmv(total, "s")
		prog = rmv(rmv(rmv(prog, " 2>&3"), "python3 "), "go run ")

		records = append(records, []string{mag_n, prog, user, system, cpu, total})
	}

	w := csv.NewWriter(os.Stdout)
	w.WriteAll(records)

	if err := w.Error(); err != nil {
		log.Fatalln("error writing csv:", err)
	}
}

func rmv(s string, old string) string {
	return strings.Replace(s, old, "", -1)
}

run.sh

#!/bin/zsh

rm -f big_loops.txt big_loops_mem.txt
touch big_loops.txt big_loops_mem.txt

# https://unix.stackexchange.com/a/126057/366399 for built-in redirect (ZSH's time cmd)
for n in '1e6' '1e7' '1e8' '1e9'; do
    for i in 1 2 3; do
        echo $n $i

        sed s/N/$n/g main.go > big_loops.go
        
        echo -n "$n " >> big_loops.txt
        { time go run big_loops.go 2>&3; } 3>&2 2>> big_loops.txt
        
        echo -n "$n big_loops.go " >> big_loops_mem.txt
        /usr/bin/time -l go run big_loops.go 2>> big_loops_mem.txt

        sed s/N/$n/g main.py > big_loops.py

        echo -n "$n " >> big_loops.txt
        { time python3 big_loops.py 2>&3; } 3>&2 2>> big_loops.txt

        echo -n "$n big_loops.py " >> big_loops_mem.txt
        /usr/bin/time -l python3 big_loops.py 2>> big_loops_mem.txt
    done
done

# Discard noisy lines, keep only timings and 'peak memory'
grep 'big_loops\|peak memory' big_loops_mem.txt > tmp
mv tmp big_loops_mem.txt 

rm big_loops.go big_loops.py