diff --git a/content/python/concepts/regex/terms/sub/sub.md b/content/python/concepts/regex/terms/sub/sub.md
index 6d08e21c41d..5feec3c1641 100644
--- a/content/python/concepts/regex/terms/sub/sub.md
+++ b/content/python/concepts/regex/terms/sub/sub.md
@@ -21,17 +21,13 @@ The **`re.sub()`** function replaces matching substrings with a new string for a
 re.sub(<pattern>, <replacement>, string, <count>, <flags>)
 ```
 
-A `<pattern>` is a [regular expression](https://www.codecademy.com/resources/docs/general/regular-expressions) that can include any of the following:
-
-- A string: `Jane Smith`
-- A character class code: `/w`, `/s`, `/d`
-- A regex symbol: `$`, `|`, `^`
-
-The other arguments include:
-
-- The replacement string (`<replacement>`): `foo`
-- An integer value for the number of replacements (`<count>`): `10`
-- `<flags>`: `IGNORECASE`, `VERBOSE`, `DOTALL`
+- `<pattern>`: A [regular expression](https://www.codecademy.com/resources/docs/general/regular-expressions) pattern used to match substrings.
+  - A string: `Jane Smith`
+  - Character class codes: `/w`, `/s`, `/d`
+  - Regex symbols: `$`, `|`, `^`
+- `<replacement>`: The replacement argument. This can either be a string or a function.
+- `<count>`: An integer specifying the number of occurrences to replace. The default is to replace all matches.
+- `<flags>`: Specifies additional options such as `IGNORECASE`, `VERBOSE`, `DOTALL`, etc.
 
 ## Example
 
@@ -40,11 +36,14 @@ The following example replaces all occurrences of "BI" with "business intelligen
 ```py
 import re
 
-blurb = '''The analytics firm uses a range of BI tools to  visualize data. Their internal data science team suggests
+def replace_business_intelligence(match):
+  return 'business intelligence'
+
+blurb = '''The analytics firm uses a range of BI tools to visualize data. Their internal data science team suggests
 bi tools may be their most valuable resource.'''
 
-match = re.sub(r'bi','business intelligence',blurb,flags=re.IGNORECASE)
-# The IGNORECASE flag allows for matches regardless of the case
+# Use the function `replace_bussines_intelligence` as the replacement argument in re.sub()
+match = re.sub(r'bi', replace_business_intelligence, blurb, flags=re.IGNORECASE)
 
 print(match)
 ```
@@ -63,10 +62,12 @@ Replace all numerical values with "REDACTED":
 ```codebyte/python
 import re
 
-confidential_str = '''The suspect's bank account (#333344444) and pin (#9999) were found in his cell'''
+def redact_numbers(match):
+  return 'REDACTED'
+
+confidential_str = '''The suspect's bank account (#333344444) and pin (#9999) were found in his cell.'''
 
-redacted = re.sub(r'\d+', 'REDACTED', confidential_str)
-# \d matches any numerical character
+redacted = re.sub(r'\d+', redact_numbers, confidential_str)
 
 print(redacted)
 ```