read_plaintext() wird zu read_text() und Text wird lower()

src/libex01.py

@@ -4,7 +4,7 @@ module to encapsulate common functions for exercise01.
 
 import string
 
-def read_plaintext(file_path):
+def read_text(file_path):
     """
     funciton to read plaintext from a file into a string variable.
     Skips non-alphabetic characters (including whitespace) and converts the rest to lower case.
@@ -12,7 +12,7 @@ def read_plaintext(file_path):
     txt = ""
     with open(file_path, "r") as _file:
         for line in _file:
-            for char in line:
+            for char in line.lower():
                 if char in string.ascii_letters:
                     txt += char
     return txt