Answer:
Here's an example program that checks whether a number entered by the user is present in a list using the 'in' operator with a 'while' loop:
copynumbers = [10, 20, 30, 40, 50]
# Ask the user for a number to check
num = int(input("Enter a number: "))
# Define a variable to keep track of whether the number is found or not
found = False
# Use a while loop to iterate through the list and check if the number is present
i = 0
while i < len(numbers):
if numbers[i] == num:
found = True
break
i += 1
# Print the result based on whether the number is found or not
if found:
print("Number is present in the list.")
else:
print("Number is not present in the list.")
Step-by-step explanation:
In this program, we first define a list of numbers. Then, we ask the user to enter a number to check. We initialize a variable `found` to keep track of whether the number is found or not.
We use a 'while' loop to iterate through the list using an index variable `i`. Inside the loop, we check if the number at the current index `i` is equal to the number entered by the user. If a match is found, we set `found` to True and break out of the loop.
After the loop, we check the value of `found` and print the appropriate message to indicate whether the number is present in the list or not.