Python Programming for Raspberry Pi, Sams Teach Yourself in 24 Hours

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  1. Press the Tab key one time to properly indent under the for loop. Now that you are
    properly indented, type my_friend = input("Friend's name: ") and
    press Enter. (You learned about getting keyboard input into a Python script in Hour 4,
    “Understanding Python Basics.” Go back there to refresh your memory if needed.)

  2. Press the Tab key one time to properly indent under the for loop. Now that you are
    properly indented, type my_friend = my_friend + '\n' and press Enter.
    Python will now add the needed newline escape sequence to the end of each friend’s
    name.

  3. Press the Tab key one time to maintain the proper indentation under the for loop.
    Type my_friends_file.write(my_friend) and press Enter. This Python
    statement causes the name to be written out to the friends.txt file.

  4. Press the Enter key two times to kick off your loop for filling the friends.txt
    file with data.

  5. Each time the loop asks you for a friend’s name, enter a name from this list and then
    press Enter:
    Chris
    Zack
    Karl
    Zoe
    Simon
    John
    Anton
    Don’t let it throw you that a number displays after each name you enter. Remember
    that the .write method displays the number of characters it wrote to a file. (Have
    you figured out who these people are yet?)

  6. So that you can now read the file from the beginning, reset the file pointer to the start
    of the file by typing my_friends_file.seek(0) and pressing Enter.

  7. Create a for loop to read the newly populated friends file by typing for
    my_friend in my_friends_file: and pressing Enter. Notice that there is
    no need to close and reopen the file. This is because in step 5, the file was opened
    with the mode w+, which allows you to write to the file and read it.

  8. Press the Tab key one time and then type print (my_friend, end=' ').
    This causes the data read into the Python script from the file to be displayed to your
    screen.

  9. Press the Enter key two times. You should see the friends’ names from the
    friends.txt file displayed to the screen.

  10. Close the friends.txt file by typing my_friends_file.close() and
    pressing the Enter key. Now the file is properly closed.

  11. Just to double-check, type my_friends_file.closed and press the Enter key.
    If the file is truly closed, you should receive back the word True. If you get False,

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