Lab 8: Reading & Writing Files
The lecture notes on files may be helpful during this part of the lab.
To get some practice reading from and writing to files, we've supplied you with the following text files in the starter directory:
nums.txt
Contains the numbers one through 10, each on its own line.nums2.txt
An alternate version ofnums.txt
.birds.txt
Contains a list of bird names, one per line.fruit.txt
Contains a list of fruits and their categories, one per line, with the fruit and category names separated by a single space.metals.txt
Contains a list of a few metallic elements, along with their densities, with a colon and a space in between the element name and density value.meetings.txt
Contains a list of meetings, with a meeting name, a start time, and a duration separated by commas. The time of day is two integers (one for the hour and one for the minutes) separated by a colon, while the duration is a floating-point number representing hours.
You will have to create your own code file for this part of the lab,
called files.py
.
Work through the exercises below...
showTop
Write a function named showTop
which accepts a file name as an
argument, and which reads that file and prints out the first three lines
of text in the file. Test it on nums.txt
, and you should see:
one
two
three
showBottom
showBottom
should work like showTop
, except it should print the
last three lines from the file instead of the first three. Testing on
nums.txt
should result in:
eight
nine
10
listLines
listLines
should accept a file name as an argument, and print the
entire contents of that file, but it should add a line number at the
start of each line, separated from the actual line by a single space. The
first line number should be 1 (not 0). Here's what the result would look
like if applied to nums.txt
:
1 one
2 two
3 three
4 4
5 five
6 six
7 seven
8 eight
9 nine
10 10
copyFile
copyFile
should take two different file names as arguments: the first argument
is the name of the original file, and the second argument is the name of the file that will store a copy of the original file.
You should open the first file, read in the contents, then open the second
file, and write out a copy of the first file (so that at the end, the two
files end up as copies of each other). Be careful that you don't
accidentally overwrite one of the starter files when you're testing this!
It won't have any return value or printed output... but you should check
that it creates an exact copy of the file you're trying to copy (you
could open both files in a text editor). You could test it with:
copyFile("birds.txt", "moreBirds.txt")
Table of Contents
- Lab 8 Home
- Part 0: Warm-Up
- Part 1: Tests & List Comprehensions
- Part 2: File Exercises
- Part 3: Secret Message
- Extra: Additional Exercises
- Knowledge Check