More Practice with Loops and Lists in Python

June 15, 2022

In this activity, you will get more practice with lists and loops.

Starter file

# Declare an empty list named `our_list`.


# Use the `append` list function to append the number 1 into `our_list`.


# Append the string "hello" into `our_list`.


# Append the boolean False into `our_list`.


# Append the number 84 into `our_list`.


# Append the string "world" into `our_list`


# Print `our_list`


# Declare a variable named `one_to_ten` and assign it a list containing the numbers from 1 to 10.


# Print the 4th element from `one_to_ten`.


# Print the 7th element from `one_to_ten`.


# We've declared this list for you
num_list = [2, 65, 3, 7, 39, 22, 11, 94, 299, 9, 20, 21, 51, 37]

# Iterate through the provided `num_list` and create an if-else statement to print every number greater than 50


# Iterate through the provided `num_list` and use the `index` function to print the index of the first occurrence of the number 11.


# Iterate through the provided `num_list` and print the sum of all the numbers.


# Iterate through the provided `num_list` and create an if-else statement to print the sum of all the numbers greater than 50.


# Iterate through the provided `num_list` and create an if-else statement to print the sum of all the even numbers.

# We've declared this list for you
fruits = [
  "Apple", "Orange", "Banana", "Pomelo", "Apple", "Kiwi", "Peach", "Banana", "Grape", "Tomato",
  "Kiwi", "Apple", "Watermelon", "Lemon", "Pomelo", "Apple", "Banana", "Peach", "Apricot", "Grape"]

# Iterate through the provided `fruits` list and print the number of times "Apple" appears in the list.


# Iterate through the provided `fruits` list and print the number of times "Peach" appears in the list.


# Iterate through the provided `fruits` list and print the number of fruits that start with "P" in the list.


## Challenge

# Create a new empty list named `unique_fruits`.


# Iterate through `fruits` and populate `unique_fruits` with only unique values from `fruits`. Hint: try looking up "not in" conditionals for if statements


# Print out the `unique_fruits` list.


# In this challenge we're going to be working with nested lists.
# You can store any type of data within an list- even other lists!
two_dim_list = [
  [54, 6, 7, 46, 78],
  [43, 9, 6, 65, 65],
  [32, 1, 44, 1, 23],
  [55, 12, 2, 34, 2],
  [2, 12, 44, 2, 12]]

# Iterate through the first list inside `two_dim_list` and print all the numbers less than 25.


# Iterate through the second list inside `two_dim_list` and print all the numbers less than 25.


# Iterate through the fifth list inside `two_dim_list` and print all the numbers less than 25.



# Iterate through `two_dim_list` and the lists inside of it and print all the odd numbers.


# Iterate through `two_dim_list` and the lists inside of it and print the sum of all the numbers that are a multiple of 3.

Instructions

Open the starter file and perform the following:

Declare an empty list named our_list.
Use the append list function to append the number 1 into our_list.
Append the string “hello” into our_list.
Append the Boolean “False” into our_list.
Append the number 84 into our_list.
Append the string “world” into our_list.
Print our_list.
Declare a variable named one_to_ten and assign it a list containing the numbers from 1 to 10.
Print the 4th element from one_to_ten.
Print the 7th element from one_to_ten.
Iterate through the provided num_list and create an if-else statement to print every number greater than 50.
Iterate through the provided num_list and use the index function to print the index of the first occurrence of the number 11.
Iterate through the provided num_list and print the sum of all the numbers.
Iterate through the provided num_list and create an if-else statement to print the sum of all the numbers greater than 50.
Iterate through the provided num_list and create an if-else statement to print the sum of all the even numbers.
Iterate through the provided fruits list and print the number of times “Apple” appears in the list.
Iterate through the provided fruits list and print the number of times “Peach” appears in the list.
Iterate through the provided fruits list and print the number of fruits that start with “P” in the list.
Execute the Python program.
- Open the command line.
- Run source activate PythonData to activate your virtual environment.
- Navigate to the directory that is holding this code drill.
- Run python filename.py to test your output.

Challenge

Create a new, empty list named unique_fruits.
Iterate through fruits and populate unique_fruits with only unique values from fruits. Hint: Look up “not in” conditionals for if statements.
Print out the unique_fruits list.
Iterate through the 1st list inside the provided two_dim_list and print all the numbers less than 25.
Iterate through the 2nd list inside two_dim_list and print all the numbers less than 25.
Iterate through the 5th list inside two_dim_list and print all the numbers less than 25.
Iterate through two_dim_list and the lists inside of it, and print all the odd numbers.
Iterate through two_dim_list and the lists inside of it, and print the sum of all the numbers that are a multiple of 3.

Solution

# Declare an empty list named `our_list`.
our_list = []

# Use the `append` list function to append the number 1 into `our_list`.
our_list.append(1)

# Append the string "hello" into `our_list`.
our_list.append("hello")

# Append the boolean False into `our_list`.
our_list.append(False)

# Append the number 84 into `our_list`.
our_list.append(84)

# Append the string "world" into `our_list`
our_list.append("world")

# Print `our_list`
print(f"Print `our_list`: {our_list}")

# Declare a variable named `one_to_ten` and assign it an list containing the numbers from 1 to 10.
one_to_ten = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

# Print the 4th element from `one_to_ten`.
print(f"Print the 4th element from `one_to_ten`: {one_to_ten[3]}")

# Print the 7th element from `one_to_ten`.
print(f"Print the 7th element from `one_to_ten`: {one_to_ten[6]}")

# We've declared this list for you
num_list = [2, 65, 3, 7, 39, 22, 11, 94, 299, 9, 20, 21, 51, 37]

# Iterate through the provided `num_list` and create an if-else statement to print every number greater than 50
print("Numbers greater than 50:")
for number in num_list:
    if number > 50:
        print(number)

# Iterate through the provided `num_list` and use the `index` function to print the index of the first occurrence of the number 11.
print("Index of first occurrence of the number 11:")
index = 0
for number in num_list:
    if number == 11:
        print(index)
    index += 1

# Iterate through the provided `num_list` and print the sum of all the numbers.
print("Sum of all numbers:")
sum = 0
for number in num_list:
    sum += number
print(sum)

# Iterate through the provided `num_list` and create an if-else statement to print the sum of all the numbers greater than 50.
print("Sum of all numbers greater than 50:")
sum = 0
for number in num_list:
    if number > 50:
        sum += number
print(sum)

# Iterate through the provided `num_list` and create an if-else statement to print the sum of all the even numbers.
print("Sum of all even numbers:")
sum = 0
for number in num_list:
    if number % 2 == 0:
        sum += number
print(sum)

# We've declared this list for you
fruits = [
  "Apple", "Orange", "Banana", "Pomelo", "Apple", "Kiwi", "Peach", "Banana", "Grape", "Tomato",
  "Kiwi", "Apple", "Watermelon", "Lemon", "Pomelo", "Apple", "Banana", "Peach", "Apricot", "Grape"]

# Iterate through the provided `fruits` list and print the number of times "Apple" appears in the list.
print("Number of times 'Apple' appears in the list:")
count = 0
for fruit in fruits:
    if fruit == "Apple":
        count += 1
print(count)

# Iterate through the provided `fruits` list and print the number of times "Peach" appears in the list.
print("Number of times 'Peach' appears in the list:")
count = 0
for fruit in fruits:
    if fruit == "Peach":
        count += 1
print(count)

# Iterate through the provided `fruits` list and print the number of fruits that start with "P" in the list.
print("Number of fruits that start with 'P':")
count = 0
for fruit in fruits:
    if fruit[0] == "p" or fruit[0] == "P":
        count += 1
print(count)

## Challenge

# Create a new empty list named `unique_fruits`.
unique_fruits = []

# Iterate through `fruits` and populate `unique_fruits` with only unique values from `fruits`. Hint: try looking up "not in" conditionals for if statements
for fruit in fruits:
    if fruit not in unique_fruits:
        unique_fruits.append(fruit)

# Print out the `unique_fruits` list.
print(f"Unique Fruits: {unique_fruits}")

# In this challenge we're going to be working with nested lists.
# You can store any type of data within an list- even other lists!
two_dim_list = [
  [54, 6, 7, 46, 78],
  [43, 9, 6, 65, 65],
  [32, 1, 44, 1, 23],
  [55, 12, 2, 34, 2],
  [2, 12, 44, 2, 12]]

# Iterate through the first list inside `two_dim_list` and print all the numbers less than 25.
print("All numbers less than 25 in the first list:")
for number in two_dim_list[0]:
    if number < 25:
        print(number)

# Iterate through the second list inside `two_dim_list` and print all the numbers less than 25.
print("All numbers less than 25 in the second list:")
for number in two_dim_list[1]:
    if number < 25:
        print(number)

# Iterate through the fifth list inside `two_dim_list` and print all the numbers less than 25.
print("All numbers less than 25 in the fifth list:")
for number in two_dim_list[4]:
    if number < 25:
        print(number)


# Iterate through `two_dim_list` and the lists inside of it and print all the odd numbers.
print("All numbers that are odd numbers in all lists:")
for one_dim_list in two_dim_list:
    for number in one_dim_list:
        if number % 2 != 0:
            print(number)

# Iterate through `two_dim_list` and the lists inside of it and print the sum of all the numbers that are a multiple of 3.
print("Sum of all numbers that are multiples of 3 in all lists:")
sum = 0
for one_dim_list in two_dim_list:
    for number in one_dim_list:
        if number % 3 == 0:
            sum += number
print(sum)