add queue tutorial

Author: twtrubiks

README.md

@@ -88,7 +88,7 @@ Python Notes 學習筆記 📝
 
 [__iter__tutorial](https://github.com/twtrubiks/python-notes/blob/master/__iter__tutorial.py) - `__iter__` tutorial
 
-[_str_tutorial.py](https://github.com/twtrubiks/python-notes/blob/master/_str_tutorial.py) - `__str__`  tutorial
+[__str__tutorial.py](https://github.com/twtrubiks/python-notes/blob/master/__str__tutorial.py) - `__str__`  tutorial
 
 [strtobool_tutorial.py](https://github.com/twtrubiks/python-notes/blob/master/strtobool_tutorial.py) - strtobool
 
@@ -160,6 +160,8 @@ Python Notes 學習筆記 📝
 
 [__call__tutorial.py](https://github.com/twtrubiks/python-notes/blob/master/__call__tutorial.py) - `__call__` tutorial  - [youtube tutorial - What is the `__call__` in python](https://youtu.be/YIstPYG15IA)
 
+[queue_tutorial.py](queue_tutorial.py) - queue tutorial
+
 ## 觀念
 
 [python_circular_import](https://github.com/twtrubiks/python-notes/tree/master/python_circular_import) - [youtube tutorial - What is Python Circular Imports](https://youtu.be/RQhN24QtDAE)

_str_tutorial.py renamed to __str__tutorial.py

@@ -0,0 +1,69 @@
+from queue import Queue
+
+
+# if the operation cannot successfully complete because the queue is either empty (cant get) or full ( cant put).
+# The default behavior is to block or idly wait until the Queue object has data or room available to
+# complete the operation.
+# You can have it raise exceptions instead by passing the block=False parameter.
+# Or you can have it wait a defined amount of time before raising an exception by passing a timeout parameter
+
+def fifo_ex():
+    # FIFO
+    lineup = Queue(maxsize=3)
+    # lineup.get(block=False)
+    lineup.put(1)
+    lineup.put(2)
+    lineup.put(3)
+    # lineup.put(4, timeout=1)
+    print('lineup.full():', lineup.full())
+    print(lineup.get())
+    print(lineup.get())
+    print(lineup.get())
+    print('lineup.empty():', lineup.empty())
+
+
+def lifo_ex():
+    # LIFO, also called stacks ()
+    # Applicable situation - concurrent
+    # why not use list
+    from queue import LifoQueue
+    stack = LifoQueue(maxsize=3)
+    stack.put(1)
+    stack.put(2)
+    stack.put(3)
+    # stack.put(4, block=False)
+    print(stack.get())
+    print(stack.get())
+    print(stack.get())
+    # stack.get(timeout=1)
+
+
+def priority_queue_ex():
+    # data structure - heap
+    # Applicable situation - product recommendation
+    from queue import PriorityQueue
+    pq = PriorityQueue()
+    pq.put((5, 'c'))
+    pq.put((2, 'a'))
+    pq.put((1, 'b'))
+    pq.put((4, 'd'))
+    while not pq.empty():
+        print(pq.get())
+
+
+def priority_queue_ex_2():
+    from queue import PriorityQueue
+    pq = PriorityQueue()
+    pq.put((-5, 'c'))
+    pq.put((-2, 'a'))
+    pq.put((-1, 'b'))
+    pq.put((-4, 'd'))
+    while not pq.empty():
+        print(pq.get())
+
+
+if __name__ == "__main__":
+    fifo_ex()
+    # lifo_ex()
+    # priority_queue_ex()
+    # priority_queue_ex_2()

queue_tutorial.py

@@ -11,3 +11,10 @@
     print('set_seqs:', set_seqs)
     set_seqs.remove('test1')
     print('set_seqs:', set_seqs)
+
+    set_1 = {"a", "b", "c", "d"}
+    set_2 = {"d", "e", "f", "g"}
+    print("All: {}".format(set_1.union(set_2)))
+    print("Both: {}".format(set_1.intersection(set_2)))
+    print("Either but not both: {}".format(
+        set_1.symmetric_difference(set_2)))