adding blacklist ability

src/utils/qdf/blacklist.rs

@@ -0,0 +1,27 @@
+use crate::utils::dateutils::{get_bdates_series_default_opt, get_min_max_real_dates};
+use crate::utils::qdf::core::*;
+use chrono::{Duration, NaiveDate};
+use polars::prelude::*;
+use std::collections::HashMap;
+use std::error::Error;
+
+use super::pivots::pivot_dataframe_by_ticker;
+
+/// The required columns for a Quantamental DataFrame.
+const QDF_INDEX_COLUMNS: [&str; 3] = ["real_date", "cid", "xcat"];
+
+pub fn create_blacklist_from_qdf(
+    df: &DataFrame,
+    metric: Option<String>,
+    start: Option<String>,
+    end: Option<String>,
+) -> Result<HashMap<String, Vec<String>>, Box<dyn Error>> {
+    // Verify that the DataFrame follows the Quantamental structure.
+    check_quantamental_dataframe(df)?;
+    let mut blacklist: HashMap<String, Vec<String>> = HashMap::new();
+
+    // Use the provided metric or default to "value".
+    let metric = metric.unwrap_or_else(|| "value".into());
+
+    Ok(blacklist)
+}