Updated Comments on upper.py (#10442)

* Updated Comments on upper.py

* Update upper.py

* Update upper.py

---------

Co-authored-by: Christian Clauss <[email protected]>

Author: its-100rabh

Diff for: strings/upper.py

@@ -1,6 +1,8 @@
 def upper(word: str) -> str:
     """
-    Will convert the entire string to uppercase letters
+    Convert an entire string to ASCII uppercase letters by looking for lowercase ASCII
+    letters and subtracting 32 from their integer representation to get the uppercase
+    letter.
 
     >>> upper("wow")
     'WOW'
@@ -11,10 +13,6 @@ def upper(word: str) -> str:
     >>> upper("wh[]32")
     'WH[]32'
     """
-
-    # Converting to ascii value int value and checking to see if char is a lower letter
-    # if it is a lowercase letter it is getting shift by 32 which makes it an uppercase
-    # case letter
     return "".join(chr(ord(char) - 32) if "a" <= char <= "z" else char for char in word)