Skip to main content

Adding count information to mapreduce output

I have data that came from sys.stdout mapper.py program as follows:

input from stdout of previous mapper.py

chevy, {mod: spark | col: brown}
chevy, {mod: equinox | col: red}
honda, {mod:civic | col:black}
honda, {mod:accord | col:white} 
honda, {mod:crv | col:pink} 
honda, {mod:hrv | col:gray} 
toyota, {mod:corola | col:white}

I would like to write a reducer.py or maybe even another mapper that takes this information and produces an output such as:

Expected output

chevy, {mod: spark | col: brown | total:2}
chevy, {mod: equinox | col: red | total:2}
honda, {mod:civic | col:black | total:4}
honda, {mod:accord | col:white | total:4} 
honda, {mod:crv | col:pink | total:4} 
honda, {mod:hrv | col:gray | total:4} 
toyota, {mod:corola | col:white | total:1}

the total is only for the keys (car brand), so chevy appears twice, honda appears 4 times, and toyota 1.

I have tried a reducer.py program and it did not work. The program I wrote looks like this:

curr_k = None
curr_v = None
k = None
curr_count = 0

for car in sys.stdin:
    car_split = car.split('|')
    k = car_split[0]
    v = car_split[1]

    if curr_k == k:
        print(curr_k, curr_v, 'total:',curr_count)
        curr_count += 1

    else:
        if curr_k:
            print(curr_k, curr_v, 'total:',curr_count)
        curr_k = k
        curr_count = 1
    
if curr_k == k:
    print(curr_k, curr_v, 'total:',curr_count)

The above code gave me the following answer:

chevy, {mod: spark | col: brown | total:1}
chevy, {mod: equinox | col: red | total:2}
honda, {mod:civic | col:black | total:1}
honda, {mod:accord | col:white | total:2} 
honda, {mod:crv | col:pink | total:3} 
honda, {mod:hrv | col:gray | total:4} 
toyota, {mod:corola | col:white | total:1}

But that is not what I am looking for.



source https://stackoverflow.com/questions/74173010/adding-count-information-to-mapreduce-output

Comments

Popular posts from this blog

Where and how is this Laravel kernel constructor called? [closed]

Where and how is this Laravel kernel constructor called? public fucntion __construct(Application $app, $Router $roouter) { } I have read the documentation and some online tutorial but I can find any clear explanation. I am learning Laravel and I am wondering where does this kernel constructor receives its arguments from. "POSTMOTERM" CLARIFICATION: Here is more clarity.I have checked the boostrap/app.php and it is only used for boostrapping the interfaces into the container class. What is not clear to me is where and how the Kernel class is instatiated and the arguments passed to the object calling the constructor.Something similar to; obj = new kernel(arg1,arg2) or, is the framework using some magic functions somewhere? Special gratitude to those who burn their eyeballs and brain cells on this trivia before it goes into a full blown menopause alias "MARKED AS DUPLICATE". To some of the itchy-finger keyboard warriors, a.k.a The mods,because I believe in th...

Why is my reports service not connecting?

I am trying to pull some data from a Postgres database using Node.js and node-postures but I can't figure out why my service isn't connecting. my routes/index.js file: const express = require('express'); const router = express.Router(); const ordersCountController = require('../controllers/ordersCountController'); const ordersController = require('../controllers/ordersController'); const weeklyReportsController = require('../controllers/weeklyReportsController'); router.get('/orders_count', ordersCountController); router.get('/orders', ordersController); router.get('/weekly_reports', weeklyReportsController); module.exports = router; My controllers/weeklyReportsController.js file: const weeklyReportsService = require('../services/weeklyReportsService'); const weeklyReportsController = async (req, res) => { try { const data = await weeklyReportsService; res.json({data}) console...

How to show number of registered users in Laravel based on usertype?

i'm trying to display data from the database in the admin dashboard i used this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count(); echo $users; ?> and i have successfully get the correct data from the database but what if i want to display a specific data for example in this user table there is "usertype" that specify if the user is normal user or admin i want to user the same code above but to display a specific usertype i tried this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count()->WHERE usertype =admin; echo $users; ?> but it didn't work, what am i doing wrong? source https://stackoverflow.com/questions/68199726/how-to-show-number-of-registered-users-in-laravel-based-on-usertype