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So far in this revision, we have worked with code which processes internal information.

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So information inside the script itself.

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So getting a string from a variable, capitalizing it.

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Maybe getting some input from a function processing it.

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So the python file was not communicating with any external files, but that is not always the case in

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real life.

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So in real applications, you have to process external files.

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That's why now we need to review.

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External file processing, and we're working with text files which are the most common.

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Type of files.

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So creating files.

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How can you create a file from Python?

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Well, using that code.

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So the open function will create a file object and that file object will be stored in this variable.

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Right?

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So file will be equal to this file object.

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Then in this file object, you have to write contents.

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So the right method.

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Belongs to this type of object.

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So it's part of the file object type and X, and it expects a string.

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So if I run that, that will create a bulk text file.

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So this is a case of writing files.

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And the key here is that you need to provide this y argument for writing.

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Now, another version of writing files, writing content to a file is this year.

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So this was just a one line string, a simple string.

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But sometimes you may want to add.

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Strings which span across multiple lines.

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In that case, you want to use a multi-line string with triple quotes here and triple quotes there.

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You store that in variable and then you apply that code again.

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And the only difference here is that you are providing the valuable content here instead of writing

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the string directly.

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You can also write the string directly.

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You can cut that and paste it here, but that is not very readable.

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It would mess up the culture.

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So whenever you have multi-line strings, please store them in a variable first and then use that variable

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in your code.

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Something to note is that if I was to run this script, it would create this book, that text file.

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Right.

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And then if I run this other script, this would override that book, the text file.

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That is because the name here and the name in here are the same.

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So this would overwrite that previous file.

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And another thing to note is that the files will be created in the project directory.

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So if you are working on Parcham, you have a dot p file where you have the code and this file will

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be created in the same folder with your dot p file.

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But if you're using a python console, then it's important to know where the python console is pointing

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to what directory it is related to.

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What did you open it from?

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So the current directory of the Python console is important here because that is where the file will

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be created in that directory.

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Then we jumped to reading files.

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The difference here is the arguments and the right methods.

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And also, of course, here we store the output of this in this variable.

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So this returns a string and the string represents the text of that file.

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So this file has to exist in the current directory, in the project directory for you to be able to

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read it.

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So for example, here, if I call this variable, I'll get this.

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Right.

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That is the text that I wrote in here.

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Up here?

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No, no.

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That we have these backslash and they symbolize break lines.

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So when you just call the variable like that in a Python console.

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You may see these as backslash ends, but if you use a print function to print that variable, then

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the backslash ends will be rendered as actual break lines.

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So we have a break line in here and we have a break line in here as well.

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Lastly, the red Lines method.

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So you see that the difference of this and that here.

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Is the methods.

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This is red lines.

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This is.

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And of course, this time I'm reading another text file.

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I did create this text file up here.

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Using the right lines method.

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So right lines is the homologue of red lines.

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Basically, with rights lines, you provides a list of strings.

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But with rights, you provide a string.

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So write lines will write each of those things in a separate line in the text file.

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And red lines will read every line as a separate string and produce a list of those lines.

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It's important to use a brake line after these lines in here if you want them to be separated in separate

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lines.

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Right.

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Then when you read this, of course you'll read it together with those backslash ends.

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As you see here, down here.

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So if you want to get rid of those ends, you can use list comprehension.

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So what I'm doing here is I am iterating through the items of the content variable of this list through

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each of these strings.

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So for each string in the content list, I am stripping out the string from those backslash ends.

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So strip will remove those characters.

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And so clean content.

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Will contain this list now.

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So clean content is the variable that we created in here.

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And that's about this video.

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We have one more and we are done.

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So assuming the next one.