Case-insensitive search in Dash Table Backend Paging with Filtering

Question

I am trying to perform a case insensitive search in the dash table which is implemented via Pagination.

Without pagination, it is working simply by putting the filter option on dash table natively.

from dash import Dash, dash_table
from dash.dependencies import Input, Output
import pandas as pd


app = Dash(__name__)

df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/gapminder2007.csv')


PAGE_SIZE = 5


app.layout = dash_table.DataTable(
    id='table-filtering',
    columns=[
        {"name": i, "id": i} for i in sorted(df.columns)
    ],
    page_current=0,
    page_size=PAGE_SIZE,
    page_action='custom',

    filter_action='custom',
    filter_query=''
)

operators = [['ge ', '>='],
             ['le ', '<='],
             ['lt ', '<'],
             ['gt ', '>'],
             ['ne ', '!='],
             ['eq ', '='],
             ['contains '],
             ['datestartswith ']]


def split_filter_part(filter_part):
    for operator_type in operators:
        for operator in operator_type:
            if operator in filter_part:
                name_part, value_part = filter_part.split(operator, 1)
                name = name_part[name_part.find('{') + 1: name_part.rfind('}')]

                value_part = value_part.strip()
                v0 = value_part[0]
                if (v0 == value_part[-1] and v0 in ("'", '"', '`')):
                    value = value_part[1: -1].replace('\\' + v0, v0)
                else:
                    try:
                        value = float(value_part)
                    except ValueError:
                        value = value_part

                # word operators need spaces after them in the filter string,
                # but we don't want these later
                return name, operator_type[0].strip(), value

    return [None] * 3


@app.callback(
    Output('table-filtering', "data"),
    Input('table-filtering', "page_current"),
    Input('table-filtering', "page_size"),
    Input('table-filtering', "filter_query"))
def update_table(page_current,page_size, filter):
    print(filter)
    filtering_expressions = filter.split(' && ')
    dff = df
    for filter_part in filtering_expressions:
        col_name, operator, filter_value = split_filter_part(filter_part)

        if operator in ('eq', 'ne', 'lt', 'le', 'gt', 'ge'):
            # these operators match pandas series operator method names
            dff = dff.loc[getattr(dff[col_name], operator)(filter_value)]
        elif operator == 'contains':
            dff = dff.loc[dff[col_name].str.contains(filter_value)]
        elif operator == 'datestartswith':
            # this is a simplification of the front-end filtering logic,
            # only works with complete fields in standard format
            dff = dff.loc[dff[col_name].str.startswith(filter_value)]

    return dff.iloc[
        page_current*page_size:(page_current+ 1)*page_size
    ].to_dict('records')


if __name__ == '__main__':
    app.run_server(debug=True)

This code filters "Asia" but not "ASIA" in the continent field. Can you please help me to find a turnaround to make it case insensitive?