add debug prints to Dataframe::with_column

Author: Michael-J-Ward

src/dataframe.rs

@@ -31,6 +31,8 @@ use datafusion::common::UnnestOptions;
 use datafusion::config::{CsvOptions, TableParquetOptions};
 use datafusion::dataframe::{DataFrame, DataFrameWriteOptions};
 use datafusion::execution::SendableRecordBatchStream;
+use datafusion::logical_expr::utils::find_window_exprs;
+use datafusion::logical_expr::LogicalPlanBuilder;
 use datafusion::parquet::basic::{BrotliLevel, Compression, GzipLevel, ZstdLevel};
 use datafusion::prelude::*;
 use pyo3::exceptions::{PyTypeError, PyValueError};
@@ -176,6 +178,56 @@ impl PyDataFrame {
     }
 
     fn with_column(&self, name: &str, expr: PyExpr) -> PyResult<Self> {
+        println!("\n\n\nadding column: {:?} with expr: {:?}", name, expr);
+        let df = self.df.as_ref().clone();
+        let plan = df.logical_plan().clone();
+        let expr = expr.expr;
+        let window_func_exprs = find_window_exprs(&[expr.clone()]);
+        println!("window_func_exprs: {:?}", window_func_exprs);
+        let (plan, mut col_exists, window_func) = if window_func_exprs.is_empty() {
+            (plan, false, false)
+        } else {
+            (
+                LogicalPlanBuilder::window_plan(plan, window_func_exprs)?,
+                true,
+                true,
+            )
+        };
+        println!("col_exists: {:?}, window_func: {:?}", col_exists, window_func);
+        println!("plan: {}", plan.display_indent());
+        
+        let new_column = expr.clone().alias(name);
+        let mut fields: Vec<Expr> = plan
+            .schema()
+            .iter()
+            .map(|(qualifier, field)| {
+                println!("qualifier: {:?}, field: {:?}", qualifier, field);
+                if field.name() == name {
+                    println!("adding new column with same name");
+                    col_exists = true;
+                    new_column.clone()
+                } else if window_func && qualifier.is_none() {
+                    println!("adding window function with alias");
+                    col(Column::from((qualifier, field))).alias(name)
+                } else {
+                    println!("adding column");
+                    col(Column::from((qualifier, field)))
+                }
+            })
+            .collect();
+
+        if !col_exists {
+            println!("col does not exist - pushing {:?}", new_column);
+            fields.push(new_column);
+        } else {
+            println!("col exists - not pushing {:?}", new_column);
+        }
+
+        let project_plan = LogicalPlanBuilder::from(plan).project(fields)?.build()?;
+        println!("project_plan: {}", project_plan.display_indent());
+        
+        
+        // Ok(DataFrame::new(df.session_state, project_plan))
         let df = self.df.as_ref().clone().with_column(name, expr.into())?;
         Ok(Self::new(df))
     }