UK Postcode

const re = new RegExp("[A-Z]{1,2}\\d[A-Z\\d]? ?\\d[A-Z]{2}", "gi");
const input = "SW1A 1AA";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

import re

pattern = re.compile(r"[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}", re.IGNORECASE)
input_text = "SW1A 1AA"
for m in pattern.finditer(input_text):
    print(m.group(0))

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(?i)[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}`)
	input := `SW1A 1AA`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}