[Concept Entry] Python: Type Hints

* intro/syntax complete

* drafted type-hints.md - ready for pr

* check fail fix

* implemented comments in review 1

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content/python/concepts/type-hints/type-hints.md

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+---
+Title: 'Type Hints'
+Description: 'Specify expected data types for variables, function arguments, and return values, improving code readability and aiding static analysis.'
+Subjects:
+  - 'Code Foundations'
+  - 'Computer Science'
+Tags:
+  - 'Python'
+  - 'Types'
+CatalogContent:
+  - 'learn-python-3'
+  - 'paths/computer-science'
+---
+
+**Type hints** in Python are a feature that enables developers to specify the expected data types of variables, function arguments, and return values. It was introduced in Python 3.5.
+
+> **Note**: Type hints are part of the **`typing` module**, which provides a comprehensive set of tools for type annotations.
+
+Type hints help developers write more robust code by allowing tools like linters and IDEs to catch type-related errors before runtime.
+
+## Syntax
+
+This is the general syntax for type hints in function annotations:
+
+```pseudo
+from typing import List, Dict, Union
+
+def function_name(parameter_name: parameter_type) -> return_type:
+  # Function body
+```
+
+- `parameter_name`: This represents the name of the parameter that the function accepts.
+- `parameter_type`: This indicates the expected data type of `parameter_name`.
+- `return_type`: This specifies the data type of the value that the function will return.
+
+### Commonly Used Type Hints
+
+- `int`, `float`, `str`, `bool`: These are the basic data types.
+- `List[ElementType]`: This is a list containing elements of `ElementType`.
+- `Dict[KeyType, ValueType]`: This is a dictionary with keys of `KeyType` and values of `ValueType`.
+- `Union[Type1, Type2]`: This is a value that can be of either `Type1` or `Type2`.
+- `Optional[Type]`: This indicates that a value can be of `Type` or `None`.
+
+> **Note**: Starting with Python 3.7, PEP 563 allows type annotations to be stored as strings and evaluated only when needed, optimizing runtime performance. From Python 3.10 onwards, PEP 604 introduces the `|` operator as a concise alternative to `Union`, simplifying syntax for type annotations.
+
+## Example
+
+This is an example of a function using type hints:
+
+```py
+from typing import List, Dict, Union
+
+def process_data(data: List[Dict[str, Union[int,str]]]) -> List[str]:
+  """
+  Processes a list of dictionaries to extract string values.
+
+  Args:
+    (data: List[Dict[str, Union[int,str]]]): A list of dictionaries including string keys and integer or string values.
+
+  PEP 604 Args:
+    (data: List[Dict[str, int | str]]): A list of dictionaries including string keys and integer or string values as per PEP 604.
+
+  Returns:
+    List[str]: A list of string values extracted from the dictionaries.
+  """
+
+  result = []
+
+  for item in data:
+    for key, value in item.items():
+      if isinstance(value, str):
+        result.append(value)
+  return result
+
+# Example usage
+data = [
+  {"name": "Alice", "age": 25},
+  {"name": "Bob", "city": "New York"}
+]
+
+output = process_data(data)
+
+print(output)
+```
+
+The above example would output the following:
+
+```shell
+['Alice', 'Bob', 'New York']
+```
+
+## Codebyte Example
+
+Here is a codebyte example demonstrating the usage of type hints:
+
+```codebyte/python
+from typing import List, Optional
+
+def greet(name: Optional[str] = None) -> str:
+  """
+  Args:
+    name (Optional[str]): Name of the person to greet. Defaults to None.
+
+  Returns:
+    str: A greeting message.
+  """
+
+  if name:
+    return f"Hello, {name}!"
+  return "Hello, World!"
+
+# Test the function
+print(greet("Dani"))
+print(greet())
+```
+
+> **Note**: While type hints enhance code clarity and facilitate static analysis during development, they do not affect how Python executes the code.