CodeAlchemy

Jotting one man's journey through software development, programming, and technology

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Keywords

yield

Very powerful and memory-efficient technique, especially for an application that handles large video files.

In Python, when you use the yield keyword in a function, you’re not creating a regular function; you’re creating a generator function.

Here’s the difference between a regular function and a generator function:

• A regular function runs from start to finish and then returns a single value (or nothing). It computes everything at once.
• A generator function doesn’t run all at once. It returns a special iterator called a generator. When you loop over this generator, the function’s code executes only until it hits a yield statement. It then “yields” (sends back) a value and pauses its execution, saving its state (all its local variables). When you ask for the next item, it resumes right where it left off. Think of it like a “pause and resume” button for your function.

Script Execution Control

__name__ == "__main__"

if __name__ == "__main__":
# the desired code

If the script is being run directly (for example, by typing python script.py in the terminal), then __name__ is set to "__main__" automatically. If the script is being imported into another script, __name__ is set to the name of the script/module (e.g., “script”).