danfo using CDN, reading writing csv or json files (maybe a bug) #468

idhamari · 2022-07-15T08:38:32Z

idhamari
Jul 15, 2022

Dear all, I am using CDN so I am trying to do simple stuff in the client side.

I can read csv file but nothing works after that e.g.

this line works:

       var df = dfd.readCSV ("test.csv").then(df => {df.head().print()});

but this one not (no output):

       var df = dfd.readCSV ("test.csv")
       df.print

or this one (no output file):

       var df = dfd.readCSV ("test.csv")
       dfd.toCSV(df, { filePath: "testOut.csv"});

risenW · 2022-07-15T08:41:35Z

risenW
Jul 15, 2022
Maintainer

Check this: https://danfo.jsdata.org/api-reference/input-output/danfo.to_csv#convert-dataframe-to-csv-string-and-download-file-in-client-side-lib

0 replies

idhamari · 2022-07-15T09:09:08Z

idhamari
Jul 15, 2022
Author

Thanks for your quick reply, it seems to work but when I try:

dfd.toCSV(df, { filePath: "testOut.csv"}); without the download option it didn't work (e.g., I want to save in the working directory not in the download folder)
using my own csv file, it didn't work. The file has a valid format and can be read and correctly using this line:
```
 var df = dfd.readCSV ("test.csv").then(df => {df.head().print()});
```

0 replies

idhamari · 2022-07-15T09:21:08Z

idhamari
Jul 15, 2022
Author

Moreover:

I tried to read the same saved file from the example e.g.

   var df = dfd.readCSV ("testOut.csv").then(df => {df.head().print()});

and I get this error:

       Uncaught (in promise) Error: Table must have a consistent number of cells.

0 replies

idhamari · 2022-07-20T07:59:08Z

idhamari
Jul 20, 2022
Author

Some notes:

It seems when saving csv, an extra empty line is written which causes the error above (shall I report a bug?) my system is Windows 10 with German localization.
```
      Uncaught (in promise) Error: Table must have a consistent number of cells.
```
The file will be saved to the download folder, and the reading will be from the working folder.

When reading a json file an error appears:

  Error: ParamError: File not supported. file must be a url or an input File object

Here is a complete example, note after saving, copy the file manually to the working folder next to the html file:

                 <!DOCTYPE html>
            <html>

                <head>
                    <meta charset="utf-8">
                    <script src="https://cdn.jsdelivr.net/npm/danfojs@1.1.0/lib/bundle.min.js"></script>
            </head>

            <body>
                <h1 style="color:rgb(95, 55, 10)"> Data Test </h1>               
            
                            <br>  
                            <button id="btnWriteCSV" type="button"   >Write CSV</button> 
                            <br>  
                            <button id="btnReadCSV"  type="button"   >Read CSV</button> 

                            <br>  
                            <button id="btnWriteJSN" type="button"   >Write JSON</button> 
                            <br>  
                            <button id="btnReadJSN"  type="button"   >Read JSON</button> 

                            <script>        
                                var myFileNameCSV= "testCSVOut.csv"                 
                                var myFileNameJSN= "testCSVOut.json"                 

                                function writeDataCSV(){
                                    console.log(" Write csv file  .............");
                                    let data = {
                                        Abs: [20.2, 30, 47.3],
                                        Count: [34, 4, 5],
                                        "country code": ["NG", "FR", "GH"]
                                    };

                                    let df = new dfd.DataFrame(data);
                                    // Note: it is saved in Downloads folder 
                                    dfd.toCSV(df, { fileName: myFileNameCSV, download: true});

                                }
            
                                function readDataCSV(){
                                    console.log(" Reading csv file  .............");
                                    // copy the file to the working folder  
                                    dfd.readCSV( myFileNameCSV ) 
                                    .then(df => {                        
                                    df.head().print()

                                    })
                                }

                                function writeDataJSN(){
                                    console.log(" Write json file  .............");
                                    let data = [
                                                    {
                                                        "Abs" : "20.2",
                                                        "Count" : "34",
                                                        "country code" : "NG",
                                                    },
                                                    {
                                                        "Abs" : "30",
                                                        "Count" : "4",
                                                        "country code" : "FR",
                                                    },
                                                    {
                                                        "Abs" : "47.3",
                                                        "Count" : "5",
                                                        "country code" : "GH",
                                                    }
                                               ]

                                    let df = new dfd.DataFrame(data);
                                    // Note: it is saved in Downloads folder 
                                    dfd.toJSON(df, { fileName: myFileNameJSN, download: true});

                                }
            
                                function readDataJSN(){
                                    console.log(" Reading json file  .............");
                                    // copy the file to the working folder  
                                    dfd.readJSON( myFileNameJSN ) 
                                    .then(df => {                        
                                    df.head().print()

                                    })
                                }
                                const buWriteCSV = document.querySelector('#btnWriteCSV');
                                buWriteCSV.addEventListener('click',  writeDataCSV);

                                const buReadCSV = document.querySelector('#btnReadCSV');
                                buReadCSV.addEventListener('click',  readDataCSV);

                                const buWriteJSN = document.querySelector('#btnWriteJSN');
                                buWriteJSN.addEventListener('click',  writeDataJSN);

                                const buReadJSN = document.querySelector('#btnReadJSN');
                                buReadJSN.addEventListener('click',  readDataJSN);
                            </script>
            </body>

            </html>

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danfo using CDN, reading writing csv or json files (maybe a bug) #468

idhamari Jul 15, 2022

Replies: 4 comments

risenW Jul 15, 2022 Maintainer

idhamari Jul 15, 2022 Author

idhamari Jul 15, 2022 Author

idhamari Jul 20, 2022 Author

idhamari
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risenW
Jul 15, 2022
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idhamari
Jul 15, 2022
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idhamari
Jul 15, 2022
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idhamari
Jul 20, 2022
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