如何从 csv 文件中提取特定对象？

Question

I am trying to get a specific part of this csv file but I cant get it to work correctly. when I try to pull a piece of it I get the entire column. Here is what the file looks like and my code:

Demand.csv

Time,Day ahead forecast,Hour ahead forecast,Current demand
00:00,23307,22058,21942
00:05,21744,21822,21849
00:10,21744,21822,21908
00:15,21744,21822,21809
00:20,21744,21615,21736
00:25,21744,21615,21688
00:30,21744,21615,21563
00:35,21744,21371,21479
00:40,21744,21371,21378
00:45,21744,21371,21256

code

const fs=require('fs')
const csv = require('csv-parser');


fs.createReadStream('demand.csv')
  .pipe(csv())
  .on('data', function(data){
    try {
        console.log(data.Time[1]);  
    }
    catch(err) {
        //error handler
        console.log('error');
    }
     })
  .on('end', function() {
    //some final operation
}); 

The Output is:

0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2

and so on till the it reaches the end of the CSV.

I have tried a couple different ways and nothing seems to have worked. I am very new to Javascript so any help is appreciated. an example of what I need is something that can pull row 3 column 1. 00:10 being the output. Thank you.

Answer 1

The problem is the 'CSV' file: your screenshot shows you had to enable multiple separator options (commas AND tabs) to use your import tool.

Try sticking to one separator: comma

Time,Day ahead forecast,Hour ahead forecast,Current demand
00:00,23307,22058,21942
00:05,21744,21822,21849
00:10,21744,21822,21908
00:15,21744,21822,21809
00:20,21744,21615,21736
00:25,21744,21615,21688
00:30,21744,21615,21563
00:35,21744,21371,21479
00:40,21744,21371,21378
00:45,21744,21371,21256

Answer 2

It appears csv-parser parses the csv into an array of objects.

To access row 3 column 1 it would be

console.log(data[3].Time);

Data is an array with each element corresponding to a 'row' of data. So to access row 3 it would be data[3] etc.

Each individual 'column' is accessed by the object key or the column header from each column in the csv .

To access object keys with spaces you can use "bracket notation"

console.log(data[3].['Day ahead forecast']);

Answer 3

So the issue could be due to no constancy Time Day ahead forecast, Hour ahead forecast, Current demand. You can fix this just like @searlea suggested with comma, tab, or evn with pipe separated.

Here's a working example.

https://repl.it/@subhendukundu/PaleWelcomeChord