Add Load A File Into The Python REPL as a Python TIL

python/load-a-file-into-the-python-repl.md

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+# Load A File Into The Python REPL
+
+I opened up a Python REPL to try some things out.
+
+```
+$ python3
+>>> import math
+>>> math.floor(5/2)
+2
+```
+
+Now, I want to reference a Python file I've been working on so that I can
+manually test the behavior of what I'm building. To do this, I can import a file
+by its name in the same way that I would import any module. Then I can use that
+namespace for class and method references. Crucially, the file should exist in
+the same directory the REPL was started from.
+
+First, here is the file:
+
+```python
+# bpe.py
+class BytePairEncoding:
+    def text_to_bytes(text: str) -> list[int]:
+        """Convert a string to a list of byte values (0-255)"""
+        return list(text.encode("utf-8"))
+```
+
+Now to use it from the REPL:
+
+```
+$ python
+>>> import bpe
+>>> bpe.BytePairEncoding.text_to_bytes("Gimme some bytes!")
+[71, 105, 109, 109, 101, 32, 115, 111, 109, 101, 32, 98, 121, 116, 101, 115, 33]
+```