Year 11 Computing — Writing and reading a file

1.The number saved here is read back and used in a sum. What does the program print?

f = open("count.txt", "w")
f.write("7")
f.close()
f = open("count.txt", "r")
n = int(f.read())
f.close()
print(n * 3)

2.The same file is opened for writing twice here, and each opening writes something different. How many lines does the file hold when this program has finished?

f = open("log.txt", "w")
f.write("first\n")
f.close()
f = open("log.txt", "w")
f.write("red\nblue\n")
f.close()

3.What comes back from readlines() is an ordinary list, so a position can be asked for out of it. Which word does this program print?

f = open("names.txt", "w")
f.write("pen\nbag\ncup\n")
f.close()
f = open("names.txt", "r")
lines = f.readlines()
f.close()
print(lines[1])

4.What is read back out of this file is turned into a number before it is used. What does the program print?

f = open("score.txt", "w")
f.write("40")
f.close()
f = open("score.txt", "r")
text = f.read()
f.close()
print(int(text) + 2)

5.This program saves three pieces of writing and then reads them back as a list. What does it print?

f = open("shades.txt", "w")
f.write("red\ngreen\nblue\n")
f.close()
f = open("shades.txt", "r")
lines = f.readlines()
f.close()
print(len(lines))

6.A program saves some writing into a file and then reads it back. Put these five things in the order they have to happen.

• Read the lines back out
• Write the lines into it
• Open the same file again with "r"
• Close the file
• Open the file with "w"

7.A program writes one of these pieces of writing into a file and then reads it back with readlines(). Match each one to the number of lines that comes back.

8.Sort each of these by whether it changes what the file holds or only looks at what is there.