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Previously, I introduced you how to dynamically insert

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the value of a variable inside a string.

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So here we constructed Hello and whatever value

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the user entered in the input function.

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So this worked with Python 2 and 3.

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This works with Python 3.6 and later versions.

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Now, what if we want to insert

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more than one value inside a string?

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How to do that?

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For example, let's say the first input function

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will ask us for the name, and the

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second will ask us for the surname.

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Let's call this variable name and this one surname.

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To use this version of string formatting with

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two variables, you'd need to do this.

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Instead of just one variable, you need to use round

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brackets and then enter all the variables you want to

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insert in the string name and surname in this case.

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Now, if you execute this, you're going to get an error.

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So you need to do something more there.

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Let's say Ardit Sulce, and you got a TypeError.

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Not all arguments converted during string formatting, which

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means that the arguments are name and surname.

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Not all of them were converted because

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only name was converted because you only

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had one placeholder here, percentage s.

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You want to have two placeholders, one for surname too.

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If you execute that well, we get another error.

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But that's not related to this line here.

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This line is perfectly fine.

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It works.

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Why does it work?

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Well, because you can see that the error happened.

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So this is where the trace back starts.

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You see that the error happens in file basics.py, which

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is the file where we have the code in line 5,

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which means that above line 5, everything is okay.

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So this line now has passed the error checking.

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It's free of errors.

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So this is the line that has

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the error, and it's a NameError.

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name user_input is not defined.

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So this user_input here has

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not been defined in our code.

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We don't have a variable with that name.

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We're just using it here.

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But we didn't define it.

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And here is a trick.

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If you don't want to execute that

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line, you can comment it out.

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So by adding this symbol here,

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Python will ignore this line.

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It will treat it as a comment,

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[Author typing]

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not as code.

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So save the script.

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Execute, enter your input as a user.

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And this is the output we get this time.

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So that was a good exercise on how to fix errors.

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Now back to our string formatting operations.

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Let's see how this now will work with two variables.

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So, user_input is not a variable anymore.

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We want to use name.

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So Hello name,

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and then we want to have a space here.

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So this is a white space.

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So name, white space, surname.

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And it's as easy as that. Execute,

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[Author typing]

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and you get the output.

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Hello, Ardit, Sulce.

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So that's the message variable, the

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string of the message variable.

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So in this way, you can put

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as many variables as you like.

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For example, what's up?

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When could be a variable today.

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The string today is part of the when variable.

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The when variable will be replaced in here by the

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value that it has, it currently has, which is today.

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Execute that.

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[Author typing]

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And that's how it works.

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And that's what you need to

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know about string formatting in Python.

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[Author typing]