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- [Instructor] In this and
the next several videos,

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we're going to take a look at

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regular expression processing in Python.

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If you're not familiar
with regular expressions,

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they are generally used for
matching patterns within text

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and once you've matched those patterns,

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you typically are going to use the results

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to do things like validate data,

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making sure that it's in the right format,

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cleaning up data to prepare
to use it in your code,

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scraping data to extract information.

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For example, you might
want to get hashtags

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out of social media posts

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and sometimes you'll use them
for transforming data as well.

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Now rarely do you ever have to create

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your own regular expressions nowadays

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because there are these
tremendous repositories out there

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that catalog regular expressions

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and help you find what you need.

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So these are just a few of the
repositories that I've used

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and there are many more out there as well.

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So if you find the need to use

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the techniques that I'm about to show you

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and you have a particular
pattern you're looking to match,

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I would go take a look at
the repositories first,

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and one of the great things about iPython

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and the interactive mode is that

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it's really easy to go ahead and work

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with regular expressions and test them out

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so that you can see if they perform

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the tasks that you need in your code.