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? …

What you'll create

Portfolio projects that showcase your new skills

Pro Logo

How you'll master it

Stress-test your knowledge with quizzes that help commit syntax to memory

Pro Logo