diff --git a/src/cmd/python.rs b/src/cmd/python.rs
index d1ac4dd3c..a6949ceb7 100644
--- a/src/cmd/python.rs
+++ b/src/cmd/python.rs
@@ -108,7 +108,8 @@ py options:
     -b, --batch <size>     The number of rows per batch to process before
                            releasing memory and acquiring a new GILpool.
                            Set to 0 to process the entire file in one batch.
-                           [default: 50000]
+                           See https://pyo3.rs/v0.21.0/memory.html#gil-bound-memory
+                           for more info. [default: 50000]
 
 Common options:
     -h, --help             Display this message
@@ -122,7 +123,7 @@ Common options:
     -p, --progressbar      Show progress bars. Not valid for stdin.
 "#;
 
-use std::{ffi::CString, fs};
+use std::fs;
 
 use indicatif::{ProgressBar, ProgressDrawTarget};
 use pyo3::{
@@ -205,22 +206,23 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
         });
     }
 
-    let expression = if let Some(expression_filepath) = args.arg_expression.strip_prefix("file:") {
-        match fs::read_to_string(expression_filepath) {
-            Ok(file_contents) => file_contents,
-            Err(e) => return fail_clierror!("Cannot load Python expression from file: {e}"),
-        }
-    } else if std::path::Path::new(&args.arg_expression)
-        .extension()
-        .is_some_and(|ext| ext.eq_ignore_ascii_case("py"))
-    {
-        match fs::read_to_string(args.arg_expression.clone()) {
-            Ok(file_contents) => file_contents,
-            Err(e) => return fail_clierror!("Cannot load .py file: {e}"),
-        }
-    } else {
-        args.arg_expression.clone()
-    };
+    let arg_expression =
+        if let Some(expression_filepath) = args.arg_expression.strip_prefix("file:") {
+            match fs::read_to_string(expression_filepath) {
+                Ok(file_contents) => file_contents,
+                Err(e) => return fail_clierror!("Cannot load Python expression from file: {e}"),
+            }
+        } else if std::path::Path::new(&args.arg_expression)
+            .extension()
+            .is_some_and(|ext| ext.eq_ignore_ascii_case("py"))
+        {
+            match fs::read_to_string(args.arg_expression.clone()) {
+                Ok(file_contents) => file_contents,
+                Err(e) => return fail_clierror!("Cannot load .py file: {e}"),
+            }
+        } else {
+            args.arg_expression.clone()
+        };
 
     let mut helper_text = String::new();
     if let Some(helper_file) = args.flag_helper {
@@ -278,22 +280,8 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
     // reuse batch buffers
     let mut batch = Vec::with_capacity(batch_size);
 
-    // safety: safe to unwrap as these are statically defined
-    let helpers_code = CString::new(HELPERS).unwrap();
-    let helpers_filename = CString::new("qsv_helpers.py").unwrap();
-    let helpers_module_name = CString::new("qsv_helpers").unwrap();
-
-    let user_helpers_code = CString::new(helper_text)
-        .map_err(|e| format!("Failed to create CString from helper text: {e}"))?;
-
-    // safety: safe to unwrap as these are statically defined
-    let user_helpers_filename = CString::new("qsv_user_helpers.py").unwrap();
-    let user_helpers_module_name = CString::new("qsv_uh").unwrap();
-
-    let arg_expression = CString::new(expression)
-        .map_err(|e| format!("Failed to create CString from expression: {e}"))?;
-
     let mut row_number = 0_u64;
+    let debug_flag = log::log_enabled!(log::Level::Debug);
 
     // main loop to read CSV and construct batches.
     // we batch python operations so that the GILPool does not get very large
@@ -324,25 +312,19 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
 
         Python::with_gil(|py| -> PyResult<()> {
             let batch_ref = &mut batch;
+            let helpers = PyModule::from_code_bound(py, HELPERS, "qsv_helpers.py", "qsv_helpers")?;
+            let batch_globals = PyDict::new_bound(py);
+            let batch_locals = PyDict::new_bound(py);
 
-            let helpers =
-                PyModule::from_code(py, &helpers_code, &helpers_filename, &helpers_module_name)?;
-            let batch_globals = PyDict::new(py);
-            let batch_locals = PyDict::new(py);
-
-            let user_helpers = PyModule::from_code(
-                py,
-                &user_helpers_code,
-                &user_helpers_filename,
-                &user_helpers_module_name,
-            )?;
+            let user_helpers =
+                PyModule::from_code_bound(py, &helper_text, "qsv_user_helpers.py", "qsv_uh")?;
             batch_globals.set_item(intern!(py, "qsv_uh"), user_helpers)?;
 
             // Global imports
-            let builtins = PyModule::import(py, "builtins")?;
-            let math_module = PyModule::import(py, "math")?;
-            let random_module = PyModule::import(py, "random")?;
-            let datetime_module = PyModule::import(py, "datetime")?;
+            let builtins = PyModule::import_bound(py, "builtins")?;
+            let math_module = PyModule::import_bound(py, "math")?;
+            let random_module = PyModule::import_bound(py, "random")?;
+            let datetime_module = PyModule::import_bound(py, "datetime")?;
 
             batch_globals.set_item("__builtins__", builtins)?;
             batch_globals.set_item("math", math_module)?;
@@ -385,8 +367,9 @@ pub fn run(argv: &[&str]) -> CliResult<()> {
                 py_row.call_method1(intern!(py, "_update_underlying_data"), (row_data,))?;
 
                 let result =
-                    match py.eval(&arg_expression, Some(&batch_globals), Some(&batch_locals)) {
-                        Ok(r) => r,
+                    match py.eval_bound(&arg_expression, Some(&batch_globals), Some(&batch_locals))
+                    {
+                        Ok(result) => result,
                         Err(e) => {
                             error_count += 1;
                             if debug_flag {