Always reproduced (ClickHouse server version 22.3.2.1):
`
udf code, python version 3.9.6
#!/usr/bin/python

import sys
import time

if __name__ == '__main__':
    for line in sys.stdin:
        print("Python4 " + line, end='')
        sys.stdout.flush()
`

SELECT test_function_python('clickhouse')

Query id: 57da3834-1238-4da6-a984-48d4c1bb4a04

┌─test_function_python('clickhouse')─┐
│ Python4 clickhouse                 │
└────────────────────────────────────┘

1 rows in set. Elapsed: 0.001 sec.

SELECT test_function_python('clickhouse') AS uuu
GROUP BY uuu

Query id: c14131e5-e7aa-4585-a9f5-8e4b3e29fe44


0 rows in set. Elapsed: 0.002 sec.

Received exception from server (version 22.3.2):
Code: 46. DB::Exception: Received from 10.254.134.108:9000. DB::Exception: Unknown function test_function_python. (UNKNOWN_FUNCTION)


SELECT uuu
FROM
(
    SELECT test_function_python('clickhouse') AS uuu
) AS tmp
GROUP BY uuu

Query id: 20ca737b-35e1-418a-ab8e-2a296ac44e28

┌─uuu────────────────┐
│ Python4 clickhouse │
└────────────────────┘

1 rows in set. Elapsed: 0.002 sec.
++i;
                continue;
            }
            
            auto args_ast = function->arguments;
            /** remove function call and take a step back to ensure
              * next iteration does not skip not yet processed data
              */
            remove_expr_at_index(i);
            
            std::remove_copy_if(
                    std::begin(args_ast->children), std::end(args_ast->children),
                    std::back_inserter(group_exprs), is_literal
            );
        }
        else if (is_literal(group_exprs[i]))
        {
            bool keep_position = false;
            if (settings.enable_positional_arguments)
            {
                const auto & value = group_exprs[i]->as<ASTLiteral>()->value;
                if (value.getType() == Field::Types::UInt64)
                {
                    auto pos = value.get<UInt64>();
                    if (pos > 0 && pos <= select_query->select()->children.size())
                        keep_position = true;
                }
            }
            if (keep_position)
                ++i;