timsaucer opened a new issue, #713:
URL: https://github.com/apache/datafusion-python/issues/713
**Is your feature request related to a problem or challenge? Please describe
what you are trying to do.**
Many users, especially those who want to try out DataFusion for the first
time will use either notebooks, either Jupyter, Databricks, or others. It would
be a nice feature to have dataframes shown in these notebooks rendered using
html like some other dataframe libraries.
**Describe the solution you'd like**
In order to do this, we need to implement `_repr_html_` on the `PyDataFrame`
object. This can operate in the same manner as `show()` and limit the output to
a few lines. Additional enhancements could include setting config parameters
for how much data to show.
**Describe alternatives you've considered**
The other alternative is to continue to use `show()` to inspect the data.
Users can output the dataframe to pandas and then use it's rendering capability.
**Additional context**
Here is a minimal demonstrable version we could start with in `PyDataFrame`
```
fn _repr_html_(&self, py: Python) -> PyResult<String> {
let mut html_str = "<table border='1'>\n".to_string();
let df = self.df.as_ref().clone().limit(0, Some(10))?;
let batches = wait_for_future(py, df.collect())?;
if batches.is_empty() {
html_str.push_str("</table>\n");
return Ok(html_str);
}
let schema = batches[0].schema();
let mut header = Vec::new();
for field in schema.fields() {
header.push(format!("<th>{}</td>", field.name()));
}
let header_str = header.join("");
html_str.push_str(&format!("<tr>{}</tr>\n", header_str));
for batch in batches {
let formatters = batch
.columns()
.iter()
.map(|c| ArrayFormatter::try_new(c.as_ref(),
&FormatOptions::default()))
.map(|c| c.map_err(|e| PyValueError::new_err(format!("Error:
{:?}", e.to_string()))))
.collect::<Result<Vec<_>, _>>()?;
for row in 0..batch.num_rows() {
let mut cells = Vec::new();
for formatter in &formatters {
cells.push(format!("<td>{}</td>", formatter.value(row)));
}
let row_str = cells.join("");
html_str.push_str(&format!("<tr>{}</tr>\n", row_str));
}
}
html_str.push_str("</table>\n");
Ok(html_str)
}
```
This produces the following example:
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