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Activity: Create loops¶
Introduction¶
As a security analyst, some of the measures you take to protect a system will involve repetition. As an example, you might need to investigate multiple IP addresses that have attempted to connect to the network. In Python, iterative statements can help automate repetitive processes like these to make them more efficient.
In this lab, you will practice writing iterative statements in Python.
Tips for completing this lab
As you navigate this lab, keep the following tips in mind:
-
### YOUR CODE HERE ###indicates where you should write code. Be sure to replace that with your own code before running the code cell. - Feel free to open the hints for additional guidance as you work on each task.
- To enter your answer to a question, double-click the markdown cell to edit. Be sure to replace the "[Double-click to enter your responses here.]" with your own answer.
- You can save your work manually by clicking File and then Save in the menu bar at the top of the notebook.
- You can download your work locally by clicking File and then Download and then specifying your preferred file format in the menu bar at the top of the notebook.
Scenario¶
You're working as a security analyst, and you're writing programs in Python to automate displaying messages regarding network connection attempts, detecting IP addresses that are attempting to access restricted data, and generating employee ID numbers for a Sales department.
Task 1¶
In this task, you'll create a loop related to connecting to a network.
Write an iterative statement that displays Connection could not be established three times. Use the for keyword, the range() function, and a loop variable of i. Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Iterative statement using `for`, `range()`, and a loop variable of `i`
# Display "Connection could not be established." three times
for i in range(3):
print("Connection could not be established.")
</div>
<div class="prompt"></div>
Hint 1
Use i as the loop variable and then place the in operator after i.
Hint 2
After the in operator, pass in the appropriate number to the range() function so that it instructs Python to repeat the specified action three times.
Task 2¶
The range() function can also take in a variable. To repeat a specified action a certain number of times, you can first assign an integer value to a variable. Then, you can pass that variable into the range() function within a for loop.
In your code that displays a network message connection, incorporate a variable called connection_attempts. Assign the positive integer of your choice as the value of that variable and fill in the missing variable in the iterative statement. Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell. Test out the code with different values for connection_attempts and observe what happens.
# Create a variable called `connection_attempts` that stores the number of times the user has tried to connect to the network
connection_attempts =3
# Iterative statement using for, range(), a loop variable of i, and connection_attempts
# Display "Connection could not be established." as many times as specified by connection_attempts
for i in range(connection_attempts):
print("Connection could not be established")
</div>
<div class="prompt"></div>
Hint 1
Assign the connection_attempts variable to a number that represents how many times the user will try to connect to the network.
Hint 2
Pass in the appropriate variable to the range() function so that it instructs Python to repeat the specified action the specified number of times.
Task 3¶
This task can also be achieved with a while loop. Complete the while loop with the correct code to instruct it to display "Connection could not be established." three times.
In this task, a for loop and a while loop will produce similar results, but each is based on a different approach. (In other words, the underlying logic is different in each.) A for loop terminates after a certain number of iterations have completed, whereas a while loop terminates once it reaches a certain condition. In situations where you do not know how many times the specified action should be repeated, while loops are most appropriate.
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign `connection_attempts` to an initial value of 0, to keep track of how many times the user has tried to connect to the network
connection_attempts = 0
# Iterative statement using while and connection_attempts
# Display "Connection could not be established." every iteration, until connection_attempts reaches a specified number
while connection_attempts < 3:
connection_attempts = connection_attempts + 1
<span class="c1"># Update `connection_attempts` (increment it by 1 at the end of each iteration) </span>
<span class="nb">print</span><span class="p">(</span><span class="s2">"Connection could not be established"</span><span class="p">)</span>
</div>
<div class="prompt"></div>
Hint 1
In the condition, use a comparison operator to check whether connection_attempts has reached a specific number. This number represents the number of times the message will be displayed.
Hint 2
In the condition, use the < comparison operator to check whether connection_attempts is less than a specific number. This number represents the number of times the message will be displayed.
Hint 3
Use the print() function to display the appropriate message to the user.
Question 1¶
What do you observe about the differences between the for loop and the while loop that you wrote?
the while loops go untill false, and for loops are for, for loops go untill it runs out of variables in the range
Task 4¶
Now, you'll move onto your next task. You'll automate checking whether IP addresses are part of an allow list. You will start with a list of IP addresses from which users have tried to log in, stored in a variable called ip_addresses. Write a for loop that displays the elements of this list one at a time. Use i as the loop variable in the for loop.
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign `ip_addresses` to a list of IP addresses from which users have tried to log in
ip_addresses = ["192.168.142.245", "192.168.109.50", "192.168.86.232", "192.168.131.147",
"192.168.205.12", "192.168.200.48"]
# For loop that displays the elements of ip_addresses one at a time
for ip_adress in ip_addresses:
print(f"{ip_adress}")
</div>
<div class="prompt"></div>
Hint 1
Use i as the loop variable and the in operator to convey that the specified action should repeat for each element that's in the list ip_addresses.
Hint 2
To display the loop variable in every iteration, use the print() function inside the for loop.
Task 5¶
You are now given a list of IP addresses that are allowed to log in, stored in a variable called allow_list. Write an if statement inside of the for loop. For each IP address in the list of IP addresses from which users have tried to log in, display "IP address is allowed" if it is among the allowed addresses and display "IP address is not allowed" otherwise.
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign `allow_list` to a list of IP addresses that are allowed to log in
allow_list = ["192.168.243.140", "192.168.205.12", "192.168.151.162", "192.168.178.71",
"192.168.86.232", "192.168.3.24", "192.168.170.243", "192.168.119.173"]
# Assign ip_addresses to a list of IP addresses from which users have tried to log in
ip_addresses = ["192.168.142.245", "192.168.109.50", "192.168.86.232", "192.168.131.147",
"192.168.205.12", "192.168.200.48"]
# For each IP address in the list of IP addresses from which users have tried to log in,
# If it is among the allowed addresses, then display “IP address is allowed”
# Otherwise, display “IP address is not allowed”
for ip_adress in ip_addresses:
if ip_adress in allow_list:
print(f"{ip_adress} allowed")
else:
print(f"{ip_adress} not allowed")
</div>
<div class="prompt"></div>
Hint 1
Use i as the loop variable and the in operator to convey that the specified action should repeat for each element that's in the list ip_addresses.
Hint 2
Make sure that the if statement checks whether the user's IP address is in list of allowed IP addresses.
Hint 3
Use the print() function to display the messages.
Task 6¶
Imagine now that the information the users are trying to access is restricted, and if an IP address outside the list of allowed IP addresses attempts access, the loop should terminate because further investigation would be needed to assess whether this activity poses a threat. To achieve this, use the break keyword and expand the message that is displayed to the user when their IP address is not in allow_list to provide more specifics. Instead of "IP address is not allowed", display "IP address is not allowed. Further investigation of login activity required".
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign `allow_list` to a list of IP addresses that are allowed to log in
allow_list = ["192.168.243.140", "192.168.205.12", "192.168.151.162", "192.168.178.71",
"192.168.86.232", "192.168.3.24", "192.168.170.243", "192.168.119.173"]
# Assign ip_addresses to a list of IP addresses from which users have tried to log in
ip_addresses = ["192.168.142.245", "192.168.109.50", "192.168.86.232", "192.168.131.147",
"192.168.205.12", "192.168.200.48"]
# For each IP address in the list of IP addresses from which users have tried to log in,
# If it is among the allowed addresses, then display “IP address is allowed”
# Otherwise, display “IP address is not allowed”
for ip_adress in ip_addresses:
if ip_adress in allow_list:
print(f"{ip_adress} allowed")
else:
print(f"{ip_adress} not allowed")
</div>
<div class="prompt"></div>
Hint 1
Use i as the loop variable and the in operator to convey that the specified action should repeat for each element that's in the list ip_addresses.
Make sure that the if statement checks whether the user's IP address is in the list of allowed IP addresses.
Use the break keyword to terminate the loop at the appropriate time.
Hint 2
Use the break keyword inside the else statement after the appropriate message is displayed.
Hint 3
Use the print() function to display the messages.
Task 7¶
You'll now complete another task. This involves automating the creation of new employee IDs.
You have been asked to create employee IDs for a Sales department, with the criteria that the employee IDs should all be numbers that are unique, divisible by 5, and falling between 5000 and 5150. The employee IDs can include both 5000 and 5150.
Write a while loop that generates unique employee IDs for the Sales department by iterating through numbers and displays each ID created.
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign the loop variable `i` to an initial value of 5000
i = 5000
# While loop that generates unique employee IDs for the Sales department by iterating through numbers
# and displays each ID created
# Generate employee IDs
while i <= 5150:
if i % 5 == 0: # Check divisibility by 5
print(i)
i += 1
</div>
<div class="prompt"></div>
Hint 1
Use a comparison operator to check whether i has reached the upper bound (which is the highest employee ID number allowed). Remember that the employee IDs need to fall between 5000 and 5150.
Make sure to update the value of the loop variable i at the end of the loop.
Hint 2
Use the <= comparison operator to check whether i has reached the upper bound, since the employee IDs need to fall between 5000 and 5150.
At the end of the loop, increment the loop variable by 5. This is because the employee IDs need to be divisble by 5 and the first employee ID is set to 5000.
Hint 3
Use the <= comparison operator to check whether i has reached 5150, since the employee IDs need to fall between 5000 and 5150.
Use the print() function to display the loop variable i in each iteration.
Use the = assignment operator and the + addition operator to increment the value of the loop variable at the end of each iteration.
Task 8¶
You would like to incorporate a message that displays Only 10 valid employee ids remaining as a helpful alert once the loop variable reaches 5100.
To do so, include an if statement in your code.
Be sure to replace the ### YOUR CODE HERE ### with your own code before you run the following cell.
# Assign the loop variable `i` to an initial value of 5000
i = 5000
# While loop that generates unique employee IDs for the Sales department by iterating through numbers
# and displays each ID created
# This loop displays "Only 10 valid employee ids remaining" once i reaches 5100
i = 5000
while i <= 5150:
print(i)
if i == 5100: #the better thing is to know the remaining number
print("Only 10 valid employee ids remaining")
i += 5
</div>
Hint 1
Use a comparison operator to check whether i has reached 5100.
Hint 2
Use the == comparison operator to check whether i has reached 5100.
Hint 3
Use the print() function to display the message.
Question 2¶
Why do you think the statement print(i) is written before the conditional rather than inside the conditional?
because in the loop we need to print the id before because its being used, then if that id is at 5100 it tells us that theres only 10 left not before. if we were to print it before printing the id we would have to say only 10 valid ids left then use up the spot and that doesnt make sense.
Conclusion¶
What are your key takeaways from this lab?
for loops are probs rly good for automating tasks
the the english way of saying how it works is, for variable in range: loop untill pass or variable = range.
additionally the while loops are used when something is true you loop untill its false
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