ch06: update from book draft

06-obj-ref/bus.py

@@ -0,0 +1,29 @@
+
+"""
+>>> import copy
+>>> bus1 = Bus(['Alice', 'Bill', 'Claire', 'David'])
+>>> bus2 = copy.copy(bus1)
+>>> bus3 = copy.deepcopy(bus1)
+>>> bus1.drop('Bill')
+>>> bus2.passengers
+['Alice', 'Claire', 'David']
+>>> bus3.passengers
+['Alice', 'Bill', 'Claire', 'David']
+
+"""
+
+# tag::BUS_CLASS[]
+class Bus:
+
+    def __init__(self, passengers=None):
+        if passengers is None:
+            self.passengers = []
+        else:
+            self.passengers = list(passengers)
+
+    def pick(self, name):
+        self.passengers.append(name)
+
+    def drop(self, name):
+        self.passengers.remove(name)
+# end::BUS_CLASS[]