Add Google Fire example

Author: gjbex

source-code/command-line-arguments/Fire/README.md

@@ -0,0 +1,10 @@
+# Fire
+
+The Google Fire library can be used to (almost) effortlessly create
+applications with a command line interface.
+
+## What is it?
+
+1. `calculator.py`: Calculator application that implements addition
+   and multiplication.
+1. `sayer.py`: Illustration of grouped commands.

source-code/command-line-arguments/Fire/calculator.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+import fire
+
+
+def add(x, y):
+    return x + y
+
+def mult(x, y):
+    return x*y
+
+
+if __name__ == '__main__':
+    fire.Fire()

source-code/command-line-arguments/Fire/sayer.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+
+import fire
+
+
+class Hello:
+
+    def __init__(self, name):
+        self.name = name
+
+    def say(self):
+        return f'Hello {self.name}'
+
+class Bye:
+
+    def __init__(self, name):
+        self.name = name
+
+    def say(self):
+        return f'Bye {self.name}'
+
+
+class Sayer:
+
+    def __init__(self, hello_name, bye_name):
+        self.hello = Hello(hello_name)
+        self.bye =  Bye(bye_name)
+
+    def say(self):
+        return f'Bla, bla'
+
+if __name__ == '__main__':
+    fire.Fire(Sayer)

source-code/command-line-arguments/README.md

@@ -7,3 +7,4 @@ How to handle command line arguments in Python scripts.
     to handle command line arguments.
   1. `Click`: illustration of how to use the click module
     to handle command line arguments.
+  1. `Fire`: command line applications using Google Fire.