#100DaysOfCode in Python Transcripts
Chapter: Appendix: Python language concepts
Lecture: Concept: Creating functions
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You just saw how to call functions.
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Now let's really quickly cover how to create functions.
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Now, I should say right when we get started that there is a lot of flexibility,
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more than most languages in Python functions and methods,
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and so we are just going to scratch the surface here,
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and not really get into all the details.
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So the keyword to define functions is def.
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We always start with def and then some function name
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and regardless whether these are methods in classes or standalone functions,
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def is the keyword and then we say the name,
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and then we have a variety of arguments or if we have no arguments,
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we can just leave this empty.
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But here we have two positional required arguments,
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we could also make these optional by specifying default values,
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we can create what are called named arguments
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where you have to say the name of the argument to pass the value
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instead of using the position.
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We can also take additional extra arguments
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that the method was not necessarily designed for, but, like I said,
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we are not going to dive too deeply into those,
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here is the basic way to define the method-
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def, name, parenthesis arguments and then colon
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to define the block that is the method.
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Here we would probably do something like validate the arguments
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like throw some kind of ValueError or something,
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if name is None or email is None, something like that.
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Then we are going to do our actual logic of the function,
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create it using the database and here we are going to somehow get that information back
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and to this db_user, maybe we want to tell whoever called
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create_user the id of the new user that was just created,
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so we'll use a return value and we'll return the id
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that was the database generated id for when we create this user.
