#100DaysOfCode in Python Transcripts
Chapter: Days 16-18: List comprehensions and generators
Lecture: Use generators to build a sequence
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A common use case I find for generators
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is to build up my sequence.
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So, let's define a list of options.
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Red, yellow, blue, white, black, green, purple.
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And in my older code, I will do something like,
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And that's fine, we just keep an internal list,
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and append to it and return it.
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Just to show you how you can do this in a more
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concise way with a generator.
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I'm just calling it the same name,
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but appending _gen.
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It's the same for loop,
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but instead of building up a new list,
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I'm going to use the yield keyword
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to yield the values one by one.
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Alright, let's see what that gives us, a generator.
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And a way to materialize the generator
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at one go is to convert it into a list,
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and there you go. So this is a shorter, more concise way
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to build up a list or sequence,
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and it's also faster if your data set grows,
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because it's evaluated lazily.
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And actually to show that in practice,
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in the next section, I will compare a list
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and a generator in performance.
