RustPython
diff --git a/‎common/src/lib.rs
+1 b/‎common/src/lib.rs
+1
diff --git a/‎common/src/str.rs
+48 b/‎common/src/str.rs
+48
diff --git a/‎vm/src/builtins.rs
+6-6 b/‎vm/src/builtins.rs
+6-6
@@ -4,3 +4,4 @@ pub mod cell;
 pub mod float_ops;
 pub mod hash;
 pub mod rc;
+pub mod str;
@@ -0,0 +1,48 @@
+pub fn get_chars(s: &str, range: std::ops::Range<usize>) -> &str {
+    let mut chars = s.chars();
+    for _ in 0..range.start {
+        let _ = chars.next();
+    }
+    let start = chars.as_str();
+    for _ in range {
+        let _ = chars.next();
+    }
+    let end = chars.as_str();
+    &start[..start.len() - end.len()]
+}
+
+pub fn zfill(bytes: &[u8], width: usize) -> Vec<u8> {
+    if width <= bytes.len() {
+        bytes.to_vec()
+    } else {
+        let (sign, s) = match bytes.first() {
+            Some(_sign @ b'+') | Some(_sign @ b'-') => {
+                (unsafe { bytes.get_unchecked(..1) }, &bytes[1..])
+            }
+            _ => (&b""[..], bytes),
+        };
+        let mut filled = Vec::new();
+        filled.extend_from_slice(sign);
+        filled.extend(std::iter::repeat(b'0').take(width - bytes.len()));
+        filled.extend_from_slice(s);
+        filled
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_get_chars() {
+        let s = "0123456789";
+        assert_eq!(get_chars(s, 3..7), "3456");
+        assert_eq!(get_chars(s, 3..7), &s[3..7]);
+
+        let s = "0유니코드 문자열9";
+        assert_eq!(get_chars(s, 3..7), "코드 문");
+
+        let s = "0😀😃😄😁😆😅😂🤣9";
+        assert_eq!(get_chars(s, 3..7), "😄😁😆😅");
+    }
+}
@@ -14,10 +14,10 @@ mod decl {
     use rustpython_parser::parser;
 
     use super::to_ascii;
+    use crate::byteslike::PyBytesLike;
     use crate::exceptions::PyBaseExceptionRef;
     use crate::function::{single_or_tuple_any, Args, KwArgs, OptionalArg, PyFuncArgs};
     use crate::obj::objbool::{self, IntoPyBool};
-    use crate::obj::objbyteinner::PyByteInner;
     use crate::obj::objbytes::PyBytesRef;
     use crate::obj::objcode::PyCodeRef;
     use crate::obj::objdict::PyDictRef;
@@ -554,18 +554,18 @@ mod decl {
     }
 
     #[pyfunction]
-    fn ord(string: Either<PyByteInner, PyStringRef>, vm: &VirtualMachine) -> PyResult<u32> {
+    fn ord(string: Either<PyBytesLike, PyStringRef>, vm: &VirtualMachine) -> PyResult<u32> {
         match string {
-            Either::A(bytes) => {
-                let bytes_len = bytes.elements.len();
+            Either::A(bytes) => bytes.with_ref(|bytes| {
+                let bytes_len = bytes.len();
                 if bytes_len != 1 {
                     return Err(vm.new_type_error(format!(
                         "ord() expected a character, but string of length {} found",
                         bytes_len
                     )));
                 }
-                Ok(u32::from(bytes.elements[0]))
-            }
+                Ok(u32::from(bytes[0]))
+            }),
             Either::B(string) => {
                 let string = string.as_str();
                 let string_len = string.chars().count();