DataFrame
The main data structure for tabular data.
Creating
DataFrame.fromColumns(data)
Create from column objects:
typescript
const df = DataFrame.fromColumns({
name: ["Alice", "Bob"],
age: [25, 30],
});DataFrame.empty(schema)
Create an empty DataFrame with a schema.
Properties
| Property | Type | Description |
|---|---|---|
shape | [number, number] | [rows, columns] |
height | number | Row count |
width | number | Column count |
Methods
Selection
| Method | Description |
|---|---|
col(name) | Get a Series by column name |
columns() | Get column names |
select(cols) | Select specific columns |
drop(cols) | Remove columns |
Filtering
| Method | Description |
|---|---|
filter(fn) | Keep rows where fn returns true |
where(col, op, val) | Filter by column condition |
head(n) | First n rows |
tail(n) | Last n rows |
Sorting
| Method | Description |
|---|---|
sort(col, asc?) | Sort by column |
Grouping
| Method | Description |
|---|---|
groupby(cols) | Group by column(s) |
GroupBy aggregations: agg({ col: op }), sum(cols), mean(cols), count(). Supported ops: sum, mean, min, max, count, first, last.
Transformation
| Method | Description |
|---|---|
rename(mapping) | Rename columns |
assign(name, values) | Add new column |
apply(fn) | Transform each row |
copy() | Deep copy |
Missing Values
| Method | Description |
|---|---|
dropna() | Remove rows with NaN |
fillna(value) | Replace NaN values |
isna() | Boolean DataFrame of NaN positions |
Combining
| Method | Description |
|---|---|
concat(dfs) | Vertical concatenation |
merge(other, opts) | SQL-like join |
unique() | Remove duplicate rows |
Display
| Method | Description |
|---|---|
print() | Print ASCII table |
toString() | Get as string |
describe() | Summary statistics |
info() | Column info |