[Edit] Python Built-In Functions: ord()

* [Edit] Python: built-in-functions: ord()

* Update ord.md

---------

Author: mamtawardhani

content/python/concepts/built-in-functions/terms/ord/ord.md

@@ -1,50 +1,184 @@
 ---
 Title: 'ord()'
-Description: 'Returns the integer that represents the Unicode character argument.'
+Description: 'Returns a number representing the unicode point for a specified character.'
 Subjects:
+  - 'Code Foundations'
   - 'Computer Science'
 Tags:
-  - 'Functions'
   - 'Characters'
+  - 'Functions'
+  - 'Strings'
   - 'Unicode'
-  - 'Integers'
 CatalogContent:
   - 'learn-python-3'
   - 'paths/computer-science'
 ---
 
-The **`ord()`** function returns the integer that represents the Unicode character argument. It is the inverse function of [`chr()`](https://www.codecademy.com/resources/docs/python/built-in-functions/chr) which provides the Unicode character for the integer passed.
+The **`ord()`** function is a built-in Python function that converts a Unicode character to its corresponding integer Unicode code point value. It essentially performs the opposite operation of the [`chr()`](https://www.codecademy.com/resources/docs/python/built-in-functions/chr) function, which converts an integer to its Unicode character.
+
+When working with text processing, character encoding, or data conversion, the `ord()` function serves as an essential tool. It allows programmers to work with the numerical representation of characters, which is helpful for various applications such as encryption algorithms, character manipulation, and data validation.
 
 ## Syntax
 
 ```pseudo
-ord(char)
+ord(character)
 ```
 
-The function takes a character argument `char` and returns the integer value that represents it in Unicode.
+**Parameters:**
+
+- `character`: A Unicode character (string of length 1). If the string contains more than one character, a `TypeError` is raised.
 
-## Example
+**Return value:**
 
-The example below demonstrates how to provide an argument to `ord()` and print the result.
+The `ord()` function returns an integer that represents the Unicode code point for the given character.
+
+## Example 1: Basic Usage of `ord()`
+
+This example demonstrates how to get the Unicode value of basic characters:
 
 ```py
-print(ord('H'))
+# Get Unicode value of uppercase letter
+print(ord('A'))
+
+# Get Unicode value of lowercase letter
+print(ord('a'))
+
+# Get Unicode value of a digit
+print(ord('5'))
+
+# Get Unicode value of a special character
+print(ord('@'))
 ```
 
-This produces the output:
+This example results in the following output:
 
 ```shell
-72
+65
+97
+53
+64
 ```
 
-## Codebyte Example
+The ASCII values for 'A', 'a', '5', and '@' are 65, 97, 53, and 64 respectively. These values are part of the Unicode standard which includes ASCII as its first 128 characters.
+
+## Example 2: Working with Non-ASCII Characters
+
+This example shows how `ord()` handles characters beyond the ASCII range, including symbols and characters from different languages:
+
+```py
+# Unicode for emoji (smiling face)
+print(ord('😀'))
+
+# Unicode for Chinese character (means "center")
+print(ord('中'))
 
-In the example below, the function `ord()` is used on each character in the string `word`. Each character is printed alongside the integer value that represents it.
+# Unicode for Russian character (Cyrillic letter)
+print(ord('Я'))
 
-> **Note:** Letters 'C' and 'c' do not return the same integer. This is because uppercase and lowercase letters are represented by different integers in Unicode.
+# Unicode for Euro symbol
+print(ord('€'))
+```
+
+This example results in the following output:
 
-```codebyte/python
-word = "Codecademy!"
-for char in word:
-  print(char, ord(char))
+```shell
+128512
+20013
+1071
+8364
 ```
+
+As shown, the `ord()` function can handle characters from any language or symbol set in the Unicode standard, returning their unique numerical code points.
+
+## Codebyte Example: Character Manipulation with `ord()`
+
+This example demonstrates a practical application of the `ord()` function in a Caesar cipher implementation, which is a basic encryption technique:
+
+```py
+def caesar_encrypt(text, shift):
+  """
+  Encrypts a text using the Caesar cipher technique.
+
+  Args:
+    text: The text to encrypt
+    shift: The number of positions to shift each letter
+
+  Returns:
+    The encrypted text
+  """
+  result = ""
+
+  for char in text:
+    # Check if character is a letter
+    if char.isalpha():
+      # Get the Unicode value
+      char_code = ord(char)
+
+      # Determine if it's uppercase or lowercase
+      base = ord('A') if char.isupper() else ord('a')
+
+      # Apply the shift (modulo 26 to wrap around the alphabet)
+      shifted_code = (char_code - base + shift) % 26 + base
+
+      # Convert back to a character
+      result += chr(shifted_code)
+    else:
+      # Keep non-alphabetic characters unchanged
+      result += char
+
+  return result
+
+# Example usage
+original_text = "Hello, World!"
+shift_value = 3
+encrypted_text = caesar_encrypt(original_text, shift_value)
+
+print(f"Original: {original_text}")
+print(f"Encrypted (shift {shift_value}): {encrypted_text}")
+```
+
+In this example, the `ord()` function converts each character to its Unicode value, apply a shift, and then convert back to a character using the `chr()` function. This demonstrates how `ord()` can be used in practical text transformation scenarios.
+
+## Frequently Asked Questions
+
+### 1. What happens if I pass more than one character to `ord()`?
+
+If you pass a string with more than one character to `ord()`, Python will raise a `TypeError`. The function is designed to work with exactly one character.
+
+```py
+try:
+  print(ord('AB'))
+except TypeError as e:
+  print(f"Error: {e}")
+```
+
+The output for this code will be:
+
+```shell
+Error: ord() expected a character, but string of length 2 found
+```
+
+### 2. What is the relationship between `ord()` and `chr()`?
+
+The `ord()` and `chr()` functions are complementary. `ord()` converts a character to its corresponding Unicode code point, while `chr()` converts a Unicode code point to its character representation.
+
+```py
+character = 'A'
+code_point = ord(character)
+print(f"ord('{character}') = {code_point}")
+
+# Convert back using chr()
+same_character = chr(code_point)
+print(f"chr({code_point}) = '{same_character}'")
+```
+
+The output for this code will be:
+
+```shell
+ord('A') = 65
+chr(65) = 'A'
+```
+
+### 3. Can `ord()` handle characters from any language?
+
+Yes, `ord()` can handle any character that is part of the Unicode standard, which contains characters from virtually all modern written languages, as well as many symbols and emojis.