File Input and Output

Apply what you've learned about Python to a real-world application.

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File Input/Output
Lesson 1 of 1
  1. 1

    Until now, the Python code you've been writing comes from one source and only goes to one place: you type it in at the keyboard and its results are displayed in the console. But what if you want to...

  2. 2

    Let's walk through the process of writing to a file one step at a time. The first code that you saw executed in the previous exercise was this: [...] This told Python to open [...] in [...]...

  3. 3

    Good work! Now it's time to write some data to a new [...] file. We added the list comprehension from the first exercise to the code in the editor. Our goal in this exercise will be to write eac...

  4. 4

    Excellent! You're a pro. Finally, we want to know how to read from our [...] file. As you might expect, we do this with the [...] function, like so: [...]

  5. 5

    What if we want to read from a file line by line, rather than pulling the entire file in at once. Thankfully, Python includes a [...] method that does exactly that. If you open a file and call ...

  6. 6

    We keep telling you that you always need to close your files after you're done writing to them. Here's why! During the I/O process, data is buffered: this means that it is held in a temporary lo...

  7. 7

    Programming is all about getting the computer to do the work. Is there a way to get Python to automatically close our files for us? Of course there is. This is Python. You may not know this, but ...

  8. 8

    It worked! Our Python program successfully wrote to [...] .

  9. 9

    Finally, we'll want a way to test whether a file we've opened is closed. Sometimes we'll have a lot of file objects open, and if we're not careful, they won't all be closed. How can we test this? ...

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File Input and Output

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