# Bytes Bytearray
bytes/bytearray can contain numbers between 0 and 255

## Overview
| What | How |
| - | - |
| `bytes` | immutable byte sequence |
| `bytes(10)` | create bytes of length 10 |
| `bytes[0]` | get first byte |
| - | - |
| `bytearray` | mutable byte sequence |
| `bytearray(10)` | create bytearray of length 10 |
| `bytearray[0]` | get first byte |
| - | - |
| *bytes from bytearray* | `bytes(bytearray)` |
| *bytearray from bytes* | `bytearray(bytes)` |
| *copy from bytearrayOrBytes* | `bytearray(bytearrayOrBytes)` |

handle both with one method:
```python
def method(data: bytearray | bytes):  # accept both types
    mydata = bytearray(data)        # copy of bytes or bytearray
```