Hello everyone,
I am happy to share my DataFrame library for D. My primary focus
was to make it simple to use and I haven't spent a lot of time
optimizing the code for memory and performance.
Example:
```d
import std.stdio;
import std.algorithm;
import std.array;
import std.range;
import dataframes;
struct Product
{
string name;
double unitPrice;
int quantity;
double discount;
double totalPrice;
}
const DISCOUNTS = [
"WELCOME": 5,
"HAPPY": 2
];
double[] applyDiscounts(Column!double values, string coupon = "")
{
auto pct = coupon in DISCOUNTS;
if (pct is null)
return iota(values.length).map!("0.0").array;
return values.map!(v => v * (*pct/100.0)).array;
}
void main(string[] args)
{
auto coupon = args.length > 1 ? args[1] : "";
auto df = new DataFrame!Product(
name: ["p1", "p2", "p3", "p4"],
unitPrice: [10.0, 15.0, 5.0, 20.0],
quantity: [3, 1, 5, 2]
);
df.discount = df.unitPrice.applyDiscounts(coupon);
df.totalPrice = (df.unitPrice - df.discount) * df.quantity;
// Preview
df.writeln;
auto total = df.rows
.map!(r => r.totalPrice)
.sum;
writeln("Total: ", total);
}
```
Highlights:
- Creates a new Class with all the fields of the given struct as
arrays.
- Supports column operations like adding two columns or
multiplying each values of the elements etc.
- `df.rows` will return the list of `Row` with only reference to
the main data.
- Easy to use with `std.algorithm` goodies (Refer README).
Add `dataframes` to your project by running,
```
dub add dataframes
```
The code and the documentation are available on GitHub
https://github.com/aravindavk/dataframes-d and
https://code.dlang.org/packages/dataframes
Please feel free to use it and let me know your experience and
suggestions.
Thanks
Aravinda
