Process management (running programs) in Intro to Computing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a new process in Python using the subprocess module.

Intro to Computing

import subprocess
subprocess.[1](['echo', 'Hello World'])

Drag options to blanks, or click blank then click option'

Alaunch

Brun

Cexecute

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'start' instead of 'run' causes an AttributeError.

Using 'execute' or 'launch' are not valid subprocess functions.

The subprocess.run() function is used to run a command in a new process and wait for it to complete.

2fill in blank

medium

Complete the code to create a new process that runs a Python script asynchronously.

Intro to Computing

import subprocess
process = subprocess.[1](['python3', 'script.py'])

Drag options to blanks, or click blank then click option'

Aexecute

Brun

Ccall

DPopen

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'run' waits for the process to finish.

Using 'call' is similar to 'run' and waits.

subprocess.Popen() starts a process asynchronously, allowing the program to continue without waiting.

3fill in blank

hard

Fix the error in the code that tries to terminate a running process.

Intro to Computing

import subprocess
proc = subprocess.Popen(['sleep', '10'])
proc.[1]()

Drag options to blanks, or click blank then click option'

Aterminate

Bend

Ckillall

Dstop

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'stop' or 'end' causes AttributeError.

Using 'killall' is not a method of Popen objects.

The terminate() method sends a signal to stop the process gracefully.

4fill in blank

hard

Fill both blanks to check if a process has finished and get its exit code.

Intro to Computing

import subprocess
proc = subprocess.Popen(['ls'])
if proc.[1]() is not None:
    exit_code = proc.[2]

Drag options to blanks, or click blank then click option'

Apoll

Bwait

Creturncode

Dexit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'wait' in first blank blocks until process ends.

Using 'exit' is not a valid attribute or method.

poll() checks if the process has finished without waiting, returning None if still running.

returncode gives the exit status of the process after it finishes.

5fill in blank

hard

Fill all three blanks to start a process, wait for it to finish, and capture its output.

Intro to Computing

import subprocess
result = subprocess.[1](['echo', 'Hello'], capture_output=[2], text=[3])
print(result.stdout)

Drag options to blanks, or click blank then click option'

Arun

BTrue

CFalse

DPopen

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Popen' does not capture output by default.

Setting capture_output or text to False returns bytes or no output.

subprocess.run() runs the command and waits for it to finish.

Setting capture_output=True captures the output.

Setting text=True returns output as a string instead of bytes.