df.append method

[onetonfoot]

I found some bugs whilst using .append which I'll try to summarize using shortcode snippets.
In addition, some things I found a little unintuitive with the API which could perhaps be improved. I'm running the latest version 1.1.1

The first append fails for empty dataframe

df = new DataFrame([], {columns: ["x"]})
df.append([[1]], [0])

However this works

df = new DataFrame([{x: 1}])
df.append([[1]], [1])

Rather oddly the same code fails when using inplace

df = new DataFrame([{x: 1}])
df.append([[1]], [1], {inplace: true})

I'm not sure if you'd consider these bugs but personally, I found it quite unintuitive

df = new DataFrame([{x: 1}])
# this append fails
df.append([{x: 2}],  [1])
# however creating a dataframe first works
df.append(new DataFrame([{x: 2}]),  [1])

I guess I was expecting that anything that is valid to construct a dataframe from would also work with append. Lastly, I found it odd that I had to pass an index for append in the first place, as append already implies the last place.

Thanks for your help and work so far, it's great to have a good DataFrame library in JS!

[risenW]

I found some bugs whilst using .append which I'll try to summarize using shortcode snippets. In addition, some things I found a little unintuitive with the API which could perhaps be improved. I'm running the latest version 1.1.1

The first append fails for empty dataframe

df = new DataFrame([], {columns: ["x"]})
df.append([[1]], [0])

However this works

df = new DataFrame([{x: 1}])
df.append([[1]], [1])

Rather oddly the same code fails when using inplace

df = new DataFrame([{x: 1}])
df.append([[1]], [1], {inplace: true})

I'm not sure if you'd consider these bugs but personally, I found it quite unintuitive

df = new DataFrame([{x: 1}])
# this append fails
df.append([{x: 2}],  [1])
# however creating a dataframe first works
df.append(new DataFrame([{x: 2}]),  [1])

I guess I was expecting that anything that is valid to construct a dataframe from would also work with append. Lastly, I found it odd that I had to pass an index for append in the first place, as append already implies the last place.

Thanks for your help and work so far, it's great to have a good DataFrame library in JS!

Thanks for these comments. I'm getting around tp fixing them now.

[velen-lqc]

When is this getting resolved? These errors are really making me move away from Danfo

[germanamz]

This bug its been around for some time is there any possible fix in the horizon? @risenW

[priyankat99]

+1

[NicHaley]

+1. Append seems pretty unusable in current state

[VirtualLands]

In order to append new row for multiple times, after failing several time, finally I succeed. The code is as below.

import * as dfd from "danfojs-node";
let obj_data = {
    'C1': ['none'],
    'C2': ['none'],
    'C3': ['none']    
}
let df = new dfd.DataFrame(obj_data);
let new_df = df.append([["none","none",'none']],[1]);
let i = 0;
let len = 10;
var X:string = "some";
var Y:string = "some";
var Z:string = "some";
while (i < len) {    
    new_df = new_df.append([[X, Y, Z]],[i+2]);   
    i++;
}

Hope that helps!