Python · Theory

Design patterns

Theory

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Design patterns

Design patterns is a practical Python topic. Explain the job in school English, then the first three steps you would actually do.

Design patterns in practice: Pygame = game loop + window. CGI = old web scripts (today: Flask). Design patterns = reusable class shapes (singleton, factory) — only when the problem needs them. Deploy = put the script on Linux/Windows with venv + a start command. IDE = VS Code / PyCharm to edit and run.

For Design patterns always — venv, requirements.txt, don’t commit secrets.

Design patterns — output — True. Singleton — one instance. Only use a pattern when the problem needs it.

Exam tip

Job in one line + three steps.

Example

# Design patterns
class School:
    _one = None
    def __new__(cls):
        if cls._one is None:
            cls._one = super().__new__(cls)
        return cls._one
print(School() is School())

Design patterns — output: True. Singleton — one instance. Only use a pattern when the problem needs it.

Short notes

DefDesign patterns — practical job.
RuleDesign patterns — three real steps.
RememberDesign patterns needs venv + requirements.
TrapSecrets in git.

Python · Theory

Design patterns

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Theory

268/268

Design patterns

Design patterns is a practical Python topic. Explain the job in school English, then the first three steps you would actually do.

For Design patterns always — venv, requirements.txt, don’t commit secrets.

Design patterns — output — True. Singleton — one instance. Only use a pattern when the problem needs it.

Exam tip

Job in one line + three steps.

Example

# Design patterns
class School:
    _one = None
    def __new__(cls):
        if cls._one is None:
            cls._one = super().__new__(cls)
        return cls._one
print(School() is School())

Design patterns — output: True. Singleton — one instance. Only use a pattern when the problem needs it.

Short notes

DefDesign patterns — practical job.
RuleDesign patterns — three real steps.
RememberDesign patterns needs venv + requirements.
TrapSecrets in git.

Design patterns

Example

Short notes

Questions

Design patterns

Example

Short notes

Questions