Amanda Sopkin - The Refactoring Balance Beam: When to Make Changes and When to Leave it Alone

Many developers struggle to find the balance between striving to improve existing code and letting good enough alone by accepting certain shortcomings. As a new developer to a team it can be difficult to understand existing strategies and patterns that are sometimes flat out bad (and often openly acknowledged as such). Often the result of tight deadlines or unclear specifications, even the best developers write code they later look back upon with shudders. So how do we decide when refactoring is worth it? Come learn strategies for refactoring with minimal impact, methods for working with bad code you can’t change, and strategies for knowing the difference between what is fixable and what is better left alone.

https://us.pycon.org/2019/schedule/presentation/213/

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6. Why refactor?
   

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7. Why refactor?
   

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17. Common Code Smell #1
    It’s too long!
    

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23. Code Smells: Long methods
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24. Tool: Replace Method with Method Object
    

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25. Tool: Replace Method with Method Object
    

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26. Tool: Introduce a parameter object
    

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28. Common Code Smell #2:
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33. Common Code Smell #3:
    OOP issues
    

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34. Code smell: Divergent change
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35. Code smell: Shotgun surgery
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36. Code smell: shotgun surgery
    

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37. Tool: Move Class
    

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38. Code smell: Parallel inheritance hierarchies
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39. Code Smell: Parallel inheritance hierarchies
    

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40. Tool: Move Class
    

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43. Tool: Extract Class
    

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44. Tool: Extract Class
    

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46. Tool: Replace Type Code with State
    

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48. Tool: Hide Delegate
    

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49. Tool: Hide Delegate
    

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52. Do I need to inherit this class?
    

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54. Lets talk Pythonic Code Smells!
    

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57. Codesmell: Unnecessary boilerplate code
    

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58. Dataclasses and attrs
    

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59. Dataclasses and attrs
    

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    (Expand) (Contract)
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107. THANK YOU!
     @amandasopkin
     

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108. Sources
     Flat Icon: https://www.flaticon.com/
     Refactoring Python by Brett Slatkin: https://www.youtube.com/watch?v=D_6ybDcU5gc
     Real Python: https://realpython.com/python-refactoring/
     Pep 20: https://www.python.org/dev/peps/pep-0020/
     Beyond Pep 8 by Raymond Hettinger: https://www.youtube.com/watch?v=wf-BqAjZb8M
     Refactoring by Martin Fowler:
     https://www.csie.ntu.edu.tw/~r95004/Refactoring_improving_the_design_of_existing_code.pdf
     

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