From 41b89407511fa80fc9020a5a60fbe677bf96c5ca Mon Sep 17 00:00:00 2001 From: Nemo Date: Sun, 26 Apr 2020 09:34:42 +0530 Subject: [PATCH] [docs] Updates docs with a WHY note --- .gitignore | 1 + README.md | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/.gitignore b/.gitignore index a7831b3..ec5a99a 100644 --- a/.gitignore +++ b/.gitignore @@ -16,3 +16,4 @@ __pycache__/ # https://bundler.io/man/bundle-install.1.html#THE-GEMFILE-LOCK # but we have zero deps, so it doesn't make sense Gemfile.lock +*.gem diff --git a/README.md b/README.md index 069ce3d..47cfc2a 100644 --- a/README.md +++ b/README.md @@ -1,14 +1,18 @@ # india-pincode-regex ![Packagist Version](https://img.shields.io/packagist/v/captn3m0/pincode?style=plastic) [![Build Status](https://travis-ci.org/captn3m0/india-pincode-regex.svg?branch=master)](https://travis-ci.org/captn3m0/india-pincode-regex) ![npm](https://img.shields.io/npm/v/pincode-validator?style=plastic) ![GitHub package.json version](https://img.shields.io/github/package-json/v/captn3m0/india-pincode-regex?style=plastic) ![GitHub](https://img.shields.io/github/license/captn3m0/india-pincode-regex?style=plastic) -Validate a [Postal Index Number][wiki] for India with a few regexes. The regexes are available in `regex.txt`. There is one regex per area code (the first digit of the PIN, which goes from 1-8). +Validate a [Postal Index Number][wiki] for India with a few regexes and zero false-positives. The regexes are available in `regex.txt`. There is one regex per area code (the first digit of the PIN, which goes from 1-8). + +## Why? + +A simple `\d{6}` approach marks a lot of invalid pincodes as valid. Out of the 900000 possible combinations, only approximately `155600` are valid pincodes in India. A simple example is `111111` which is an invalid pincode, but any simple 6 digit-check will pass it as a valid one. ## Source -The source for the data is the ["All India Pincode Directory"](https://data.gov.in/resources/all-india-pincode-directory) dataset on data.gov.in. +The source for the data is the ["All India Pincode Directory"](https://data.gov.in/resources/all-india-pincode-directory) dataset on data.gov.in. The last updated date for the dataset is currently 30th May 2019. ## Usage -The `regex.txt` file is 32KB in size, so you can easily use it wherever you want, including browsers. +The `regex.txt` file is 32KB in size, so you can easily use it wherever you want, including browsers. If you are using any of the packages below, this is already delivered compressed. ### PHP