Error on printing rx

[ahuang11]

Trying to figure out what's an rx object and not by printing, but it ends up raising an error.

from io import BytesIO
import pandas as pd
import panel as pn
pn.extension()

@pn.cache
def get_stocks(data):
    if data is None:
        stock_file = 'https://datasets.holoviz.org/stocks/v1/stocks.csv'
    else:
        stock_file = BytesIO(data)
    return pd.read_csv(stock_file, index_col='Date', parse_dates=True)


file_input = pn.widgets.FileInput(sizing_mode='stretch_width')

stocks = pn.rx(get_stocks)(file_input)

selector = pn.widgets.MultiSelect(
    name='Select stocks', sizing_mode='stretch_width',
    options=stocks.columns.to_list()
)

selected_stocks = stocks.rx.pipe(
    lambda df, cols: df[cols] if cols else df, selector
)

print(selected_stocks)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[3], line 28
     19 selector = pn.widgets.MultiSelect(
     20     name='Select stocks', sizing_mode='stretch_width',
     21     options=stocks.columns.to_list()
     22 )
     24 selected_stocks = stocks.rx.pipe(
     25     lambda df, cols: df[cols] if cols else df, selector
     26 )
---> 28 print(selected_stocks)

TypeError: __str__ returned non-string (type rx)