Updated comments on the patterns

Author: dancergraham

chapter05_singleton/readme.md

@@ -2,4 +2,4 @@
 
 > **Singleton**: ensures a class has only one instance, and provides a global point of access to it.
 
-Based this [stackoverflow post](https://stackoverflow.com/questions/6760685/creating-a-singleton-in-python?noredirect=1&lq=1).
+My implementation is based this [stackoverflow post](https://stackoverflow.com/questions/6760685/creating-a-singleton-in-python?noredirect=1&lq=1).

chapter06_command/readme.md

@@ -2,4 +2,6 @@
 
 > **Command**: Encapsulates a request as an object, thereby letting you parameterise clients with different requests, queue or log requests, and support undoable operations.
 
+## Use in Python
+
 [Threading](https://docs.python.org/3/library/threading.html) In the Python standard library follows the command design pattern: The _Client_ is the main thread and the _receiver_ is the target thread.  The _Command_ is a callable Python object which is executed by calling its `__call__()` method. The _Invoker_ is the `Thread` instance and its `run()` method is equivalent to calling _execute_ in the Command pattern. `Thread`'s `run` method can be overridden in subclasses to customise the functionality beyond simply providing a function and input `args` and `kwargs`.

chapter07_adapter_facade/readme.md

@@ -2,4 +2,9 @@
 
 > **Adapter**: Converts the interface of a class into another interface the clients expect. Adapter lets classes work together that couldn't otherwise because of incompatible interfaces.
 
+Compiled C modules in Python could be seen as examples of the adapter pattern: the Python implementation provides an interface for python code to work with the incompatible underlying C code.
+
 > **Façade**: Provides a unified interface to a set of interfaces in a subsystem.  Façade defines a higher-level interface that makes the subsystem easier to use.
+
+The [pathlib](https://github.com/python/cpython/blob/main/Lib/pathlib.py) Python library provides a simplified high-level cross-platform interface to methods and attributes from the `os`, `sys`, `io` and other modules.
+