adapter

Adapter Design Pattern

Videos

Section	Video Links
Adapter Overview
Adapter Use Case
Python isinstance() Function
Python time Module

Book

Cover	Links
	https://www.amazon.com/dp/B08XLJ8Z2J    https://www.amazon.co.uk/dp/B08XLJ8Z2J    https://www.amazon.in/dp/B08Z282SBC    https://www.amazon.de/dp/B08XLJ8Z2J    https://www.amazon.fr/dp/B08XLJ8Z2J    https://www.amazon.es/dp/B08XLJ8Z2J    https://www.amazon.it/dp/B08XLJ8Z2J    https://www.amazon.co.jp/dp/B08XLJ8Z2J    https://www.amazon.ca/dp/B08XLJ8Z2J    https://www.amazon.com.au/dp/B08Z282SBC

Overview

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Terminology

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Adapter UML Diagram

Source Code

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Output

python ./adapter/adapter_concept.py
method A
method B
method A
method B

Example Use Case

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Example UML Diagram

Output

python ./adapter/client.py
Company A is busy, trying company B
Company B is busy, trying company A
Company A is busy, trying company B
Company B is busy, trying company A
Company A building Cube id:2968196317136, 2x3x7
Company A is busy, trying company B
Company B building Cube id:2968196317136, 8x2x8
Company A building Cube id:2968196317040, 4x6x4
Company A is busy, trying company B
Company B is busy, trying company A
Company A building Cube id:2968196317136, 5x4x8
Company A is busy, trying company B
Company B building Cube id:2968196317136, 2x2x9
5 cubes have been manufactured

New Coding Concepts

Python isinstance() Function

Syntax: isinstance(object, type)

Returns: True or False

You can use the inbuilt function isinstance() to conditionally check the type of an object.

>>> isinstance(1,int) 
True
>>> isinstance(1,bool) 
False
>>> isinstance(True,bool) 
True
>>> isinstance("abc",str)    
True
>>> isinstance("abc",(int,list,dict,tuple,set)) 
False
>>> isinstance("abc",(int,list,dict,tuple,set,str)) 
True

You can also test your custom classes.

class my_class:
    "nothing to see here"

CLASS_A = my_class()
print(type(CLASS_A))
print(isinstance(CLASS_A, bool))
print(isinstance(CLASS_A, my_class))

Outputs

<class '__main__.my_class'>
False
True

You can use it in logical statements as I do in /adapter/adapter_concept.py.

Python time Module

The time module provides time related functions, most notably in my case, the current epoch (ticks) since January 1, 1970, 00:00:00 (UTC) .

The time module provides many options that are outlined in more detail at https://docs.python.org/3/library/time.html

In /adapter/cube_a.py, I check the time.time() at various intervals to compare how long a task took.

    now = int(time.time())
    if now > int(CubeA.last_time + 1):
        CubeA.last_time = now
        return True

I also use the time module to sleep for a second between loops to simulate a 1 second delay. See /adapter/client.py

    # wait some time before manufacturing a new cube
    time.sleep(1)

When executing /adapter/cube_a.py you will notice that the process will run for about 10 seconds outputting the gradual progress of the construction of each cube.

Summary

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