# Zhi Yuan "Oscar" Lin # 23 October 2021 # In this lesson, I learned how to modify and insert element(s) in a list through examples and tasks. Additionally, I # learned more concerning the mistakes a programmer should look out for when using a list(s). For example, I learned a # new error type called, "AttributeError". # There were no major problems or questions throughout this lesson.

# [ ] review and run example # the list before Insert # The variable "party_list" is assigned to a list of strings. party_list = ["Joana", "Alton", "Tobias"] # This function displays the string "party_list before: " and the value assigned to the party_list variable in the output. print("party_list before: ", party_list) # the list after Insert # This line of code replaces the valaue in the index position 1, that is in the value assigned to the party_list variable, # with the string "Colette". party_list[1] = "Colette" # This function displays the string "party_list after: " and the value assigned to the party_list in the output. print("party_list after: ", party_list)

# [ ] review and run example # The variable "party_list" is assigned to a list of strings. party_list = ["Joana", "Alton", "Tobias"] # This function displays the string "before:" and the value assigned to party_list variable in the output. print("before:",party_list) # modify index value # This line of code replaces the value in the index position 1, that is in the value assigned to the party_list variable, # with the concatenated string formed from the value in the index position 1 and the string " Derosa". party_list[1] = party_list[1] + " Derosa" # This function displays the stirng "after:" and the value assigned to the party_list variable in the output. Additionally, # they are displayed on the next line due to the escape character "/n". print("\nafter:", party_list)

# IndexError Example # [ ] review and run example which results in an IndexError # if result is NameError run cell above before running this cell # IndexError trying to append to end of list # This examples provides an example of what an IndexError is. This example contains an IndexError due to the line of code # written to replace the value in the index position 3, that is in the in the value assigned to the party_list variable, # when there is no value in the index position 3. # This line of code replaces the value in the index position 3, that is in the value assigned to the party_list variable, # with the string "Alton". party_list[3] = "Alton" # This function displays the value assigned to the party_list variable in the output. print(party_list)

# [ ] review and run example changes the data type of an element # replace a string with a number (int) # The variable "single_digits" is assigned to a list of strings. single_digits = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"] # This function displays the string "single_digits: " and the value assigned to the single_digits variable in the output. print("single_digits: ", single_digits) # This function displays the string "single_digits[3]", the value that is in the index position 3 of the value assigned # to the single_digits variable, and the type of the value that is in the index position 3 of the value assigned to the # single_digits variable, in the output. Additionally, a blank line will be displayed on the next line of the output due # to the escape character "\n". print("single_digits[3]: ", single_digits[3], type(single_digits[3]),"\n") # replace string with an int # This line of code replaces the value in the index position 3, that is in the value assigned to the single_digits variable, # with the integer "3". single_digits[3] = 3 # This function displays the string "single_digits: " and the value assigned to the single_digits variable in the output. print("single_digits: ", single_digits) # This function displays the string "single_digits[3]", the value that is in the index position 3 of the value assigned # to the single_digits variable, and the type of the value that is in the index position 3 of the value assigned to the # single_digits variable, in the output. print("single_digits[3]: ", single_digits[3], type(single_digits[3]))

# [ ] complete "replace items in a list" task # The variable "three_num" is assigned to a list of integers. three_num = [2, 4, 6] # This function displays the value assigned to the three_num variable in the output. print(three_num) # This IF statement determines if the value in the index position 0, that is in the value assigned to the three_num # variable, is less than, <, the integer "5". If true, the value in index position 0 will be replaced by the string # small. If false, the program moves on to the else statement with the string "large" replacing the value in the # index position 3. if three_num[0] < 5: three_num[0] = "small" else: three_num[0] = "large" # This function displays the value assigned to the three_num variable in the output. print(three_num)

# [ ] create challenge function # The variable "int_list" is assigned to a list of integers. int_list = [2, 4, 8] # This program defines a function named "str_replace", that has the parameters "int_list" and "index", with an IF statement. # The if statement determines if the value in the index position, which depends on the integer assigned to the index # parameter, in the value assigned to the int_list variable is less than, <, the integer "5". If true, the value in that # index position in the value assigned to the int_list variable will be replace by the string "small". If false, the # program moves on to the else statement and replaces the value in that index position in the value assigned to the int_list # variable will be replace by the string "large". Subsequently, the value assigned to int_list variable will be return by # the keyword "return". def str_replace(int_list, index): if int_list[index] < 5: int_list[index] = "small" else: int_list[index] = "large" return int_list # This line of code calls the str_replace() function with the arguments "int_list", and "0". Due to their placement, the # int_list variable is assigned to the int_list parameter parameter while the integer "0" is assigned to the index parameter. str_replace(int_list, 0)

# [ ] complete coding task described above # The variable "three_words" is assigned to a list of strings. three_words = ["Apple", "Orange", "Lemon"] # This function displays the value assigned to the three_words variable in the output. print(three_words) # This line of code replaces the value in the index position 0, in the value assigned to the three_words variable, # with value in the index position 0 being changed into uppercases due to it being attached to the string method # ".upper()". three_words[0] = three_words[0].upper() # This line of code replaces the value in the index position 2, in the value assigned to the three_words variable, # with value in the index position 2 being changed from lowercases to uppercases and uppercases to lowercases due to # it being attached to the string method ".swapcase()". three_words[2] = three_words[2].swapcase() # This function displays the value assigned to the three_words variable in the output. print(three_words)

# [ ] review and run example # the list before Insert # The variable "party_list" is assigned to a list of strings. party_list = ["Joana", "Alton", "Tobias"] # This function displays the string "party_list before: " and the value assigned to the party_list variable in the output. print("party_list before: ", party_list) # This function displays the string "index 1 is", the value in the index position 1 that is in the list of strings of the # party_list variable, the string "index 2 is", and the value in the index position 2, in the output. Additionally, the # string "index 2 is" and the value in the index position 2 will be displayed on the next line in the output due to the # escape character "\n". After that, there will also be a blank line on the next line in the output because of the escape # character "\n". print("index 1 is", party_list[1], "\nindex 2 is", party_list[2], "\n") # the list after Insert # This line of code adds the string "Colette" to the index position 1 that is in the value assigned to the party_list # variable due to the ".insert()" method. party_list.insert(1,"Colette") # This function displays the string "party_list after: " and the value assigned to the party_list in the output. print("party_list after: ", party_list) # This function displays the string "index 1 is", the value in the index position 1 that is in the list of strings of the # party_list variable, the string "index 2 is", the value in the index position 2 , the string "index 3 is", and the value # in the index position 3, in the output. Additionally, the string "index 2 is" and the value in the index position 2 will # be displayed on the next line in the output due to the escape character "\n". After that, the string "index 3 is" and the # value in the index position 3 will be on the next line in the output because of the escape character "\n". print("index 1 is", party_list[1], "\nindex 2 is", party_list[2], "\nindex 3 is", party_list[3])

# [ ] insert a name from user input into the party_list in the second position (index 1) # The variable "party_list" is assigned to a list of strings. party_list = ["Joana", "Alton", "Tobias"] # The entry the user inputs, when presented with the string "Enter a name: ", will be add to the index position 1 # in the value assigned to the party_list variable due to the ".insert()" method. party_list.insert(1, input("Enter a name: ")) # [ ] print the updated list # This function displays the value assigned tnhn o the party_list variable in the output. print(party_list)

# [ ] Fix the Error # This program originally contained an AttributeError due to the code that tries to add the string "pine" to the index # position 1 in the value assigned to the tree_list variable. However, the value assigned to the tree_list variable is not a # list but a string. This is fixed by changing the string" "oak" into a list by placing '"oak"' within sqaure brackets. # The variable "tree_list" is assigned to a list that has one string. tree_list = ["oak"] # This function displays the string "tree_list before =" and the value assigned to the tree_list variable in the output. print("tree_list before =", tree_list) # This line of code adds the string "pine" to the index position 1 in the value assigned to the tree_list variable due to # the ".insert " method. tree_list.insert(1,"pine") # This function displays the string "tree_list after =" and the value assigned to the tree_list variable in the output. print("tree_list after =", tree_list)