# Zhi Yuan "Oscar" Lin # 5 November 2021 # In this lesson, I learned how to use the ".readline()" and ".strip()" methods through examples and functions. # Additionally, I learned more regarding how to importing opening, and closing a file. # There were no major problems or questions throughout this lesson.

# [ ]Run to download file poem1.txt # This program imports a file named "poem1.txt" by using the !curl command. !curl https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/poem1.txt -o poem1.txt

# [ ] review and run example # open address to file # The variable "poem1" is assigned to the return file object from using the open() function to open the file named # "poem1.txt" in read mode, and text mode by default. poem1 = open('poem1.txt', 'r')

# [ ] review and run example # readline 1, 2, 3 # The variable "poem_line1" is assigned to the string form of the first line of the value assigned to the poem_1 variable # due to the file method ".readline()". poem_line1 = poem1.readline() # The variable "poem_line2" is assigned to the string form of the second line of the value assigned to the poem_1 variable # due to the file method ".readline()". poem_line2 = poem1.readline() # The variable "poem_line3" is assigned to the string form of the third line of the value assigned to the poem_1 variable # due to the file method ".readline()". poem_line3 = poem1.readline()

# [ ] review and run example: print the first 3 .readline() values # This function displays the concatenated string formed from the value assigned to the poem_line1 variable, the value # assigned to the poem_line2 variable, and the value assigned to the poem_line3 variable, in the output. print(poem_line1 + poem_line2 + poem_line3)

# [ ] review and run example printing return value & re-run several times # This function displays the string form of the fourth line of the value assigned to the poem_1 variable, due to the file # method ".readline()". If one re-runs several times, the function will display the remaining lines of the value assigned # to the poem1 variable. print(poem1.readline())

# [ ] review and run example to close file in memory- then run previous cell # This program removes the reference created by the file open() function that is assigned to the poem1 variable, by using # the file method ".close()". poem1.close()

# [ ] import https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/rainbow as rainbow.txt # This program imports a file named "rainbow.txt" by using the !curl command. !curl https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/rainbow -o rainbow.txt

# [ ] open rainbow.txt as rainbow_text # The variable "rainbow_text" is assigned to the return file object from using the open() function to open the file named # "rainbow.txt" in read mode and text mode by default. rainbow_text = open('rainbow.txt')

# [ ] read the first 3 lines into variables: color1, color2, color3 # The variable "color1" is assigned to the string form of the first line of the value assigned to the rainbow_text variable # due to the file method ".readline()". color1 = rainbow_text.readline() # The variable "color2" is assigned to the string form of the first line of the value assigned to the rainbow_text variable # due to the file method ".readline()". color2 = rainbow_text.readline() # The variable "color3" is assigned to the string form of the first line of the value assigned to the rainbow_text variable # due to the file method ".readline()". color3 = rainbow_text.readline()

# [ ] close rainbow.txt # This program removes the reference created by the file open() function that is assigned to the rainbow_text variable, by # using the file method ".close()". rainbow_text.close()

# [ ] print the first 3 colors # This function displays the value assigned to the color1 variable in the output. print(color1) # This function displays the value assigned to the color2 variable in the output. print(color2) # This function displays the value assigned to the color3 variable in the output. print(color3)

# [ ] review and run example # open address to file # The variable "poem1" is assigned to the return file object from using the open() function to open the file named # "poem1.txt" in read mode, and text mode by default. poem1 = open('poem1.txt', 'r')

# [ ] review and run example - use a while loop to read each line of a file # remove last character ('\n') and print as upper case # The variable "poem_line" is assigned to the string form of the first line of the value assigned to the poem1 variable by # using the file method ".readline()". poem_line = poem1.readline() # In this case, the while loop is followed by the variable "poem_line". Hence, it will evaluate true as long there there is # a value assigned to the poem_line variable. Additionally, the codes that are indented and follow the while loop will # be part of the loop. Thus, the loop starts with the value assigned to the poem_line variable being display in the output, # after the last character is removed and the value being changed into all uppercases due to the string method ".upper()". # Subsequently, the poem_line variable will be reassigned to the string form of the next line of the value assigned to the # poem1 variable, due to the file method ".readline()". This loop will continue until the while loop evaluates false. while poem_line: print(poem_line[:-1].upper()) poem_line = poem1.readline()

# [ ] review and run example # This program removes the reference created by the file open() function that is assigned to the poem1 variable, by # using the file method ".close()". poem1.close()

# [ ] open rainbow.txt as rainbow_text as read-only # The variable "rainbow_text" is assigned to the return file object from using the open() function to open the file named # "rainbow.txt" in read mode, and text mode by default. rainbow_text = open('rainbow.txt', 'r')

# [ ] read the color from lines of rainbow_text in a while loop # [ ] print each color capitalized as the loop runs # The variable "rainbow_line" is assigned to the string form of the first line of the value assigned to the rainbow_text # variable due to the file method ".readline()". rainbow_line = rainbow_text.readline() # In this case, the while loop is followed by the variable "rainbow_line". Hence, it will evaluate true as long there there # is a value assigned to the rainbow_line variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the rainbow_line variable being display in the # output, after the value is capitalized due to the string method ".capitalize()". Subsequently, the rainbow_line variable # will be reassigned to the string form of the next line of the value assigned to the rainbow_text variable, due to the file # method ".readline()". This loop will continue until the while loop evaluates false. while rainbow_line: print(rainbow_line.capitalize()) rainbow_line = rainbow_text.readline()

# [ ] close rainbow_text # This program removes the reference created by the file open() function that is assigned to the rainbow_text variable, by # using the file method ".close()". rainbow_text.close()

# [ ] review and run example # open address to file # The variable "poem1" is assigned to the return file object from using the open() function to open the file named # "poem1.txt" in read mode, and text mode by default. poem1 = open('poem1.txt', 'r')

# [ ] review and run example - readline while loop without removing '\n' # The variable "poem_line" is assigned to the string form of the first line of the value assigned to the poem1 variable by # using the file method ".readline()". poem_line = poem1.readline() # In this case, the while loop is followed by the variable "poem_line". Hence, it will evaluate true as long there there # is a value assigned to the poem_line variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the poem_line variable being display in the # output. Subsequently, the poem_line variable will be reassigned to the string form of the next line of the value assigned # to the poem1 variable, due to the file method ".readline()". This loop will continue until the while loop evaluates false. while poem_line: print(poem_line) poem_line = poem1.readline() # This program removes the reference created by the file open() function that is assigned to the poem1 variable, by # using the file method ".close()". poem1.close()

# [ ] review and run example - readline with .strip() to remove '\n' # The variable "poem1" is assigned to the return file object from using the open() function to open the file named # "poem1.txt" in read mode, and text mode by default. poem1 = open('poem1.txt', 'r') # The variable "poem_line" is assigned to the string form of the first line of the value assigned to the poem1 variable by # using the file method ".readline()", after the leading and trailing whitespace in the value assigned to the poem1 variable # are removed due to it being attached to the .strip() method. poem_line = poem1.readline().strip() # In this case, the while loop is followed by the variable "poem_line". Hence, it will evaluate true as long there there # is a value assigned to the poem_line variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the poem_line variable being display in the # output. Subsequently, the poem_line variable will be reassigned to the string form of the next line of the value assigned # to the poem1 variable, due to the file method ".readline()", after the leading and trailing whitespace in the value # assigned to the poem1 variable are removed due it being attrached to the .strip() method. This loop will continue until # the while loop evaluates false. while poem_line: print(poem_line) poem_line = poem1.readline().strip() # This program removes the reference created by the file open() function that is assigned to the poem1 variable, by # using the file method ".close()". poem1.close()

# [ ] open rainbow.txt as rainbow_text as read-only # The variable "rainbow_text" is assigned to the return file object from using the open() function to open the file named # "rainbow.txt" in read mode, and text mode by default. rainbow_text = open('rainbow.txt', 'r')

# [ ] read a color from each line of rainbow_text in a while loop # use .strip to remove the whitespace '\n' character # print each color upper case # The variable "rainbow_line" is assigned to the string form of the first line of the value assigned to the rainbow_text # variable due to the file method ".readline()", after the leading and trailing whitespace in the value assigned to the # rainbow_text are removed due to it being attached to the .strip() method. rainbow_line = rainbow_text.readline().strip() # In this case, the while loop is followed by the variable "rainbow_line". Hence, it will evaluate true as long there there # is a value assigned to the rainbow_line variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the rainbow_line variable being display in the # output, after the value is changed into all uppercases due to the string method ".upper()". Subsequently, the rainbow_line # variable will be reassigned to the string form of the next line of the value assigned to the rainbow_text variable, due # to the file method ".readline()", after the leading and trailing whitespace in the value assigned to the rainbow_text # variable are removed due it being attrached to the .strip() method. This loop will continue until the while loop evaluates # false. while rainbow_line: print(rainbow_line.upper()) rainbow_line = rainbow_text.readline().strip()

# [ ] review and run example: import rainbow_messy.txt # This program imports a file named "rainbow_messy.txt" by using the !curl command. !curl https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/rainbow_messy -o rainbow_messy.txt

# [ ] review and run example: open file read only # The variable "rainbow_messy" is assigned to the return file object from using the open() function to open the file named # "rainbow_messy.txt" in read mode, and text mode by default. rainbow_messy = open('rainbow_messy.txt', 'r')

# [ ] review and run example: .readline() without .strip() # The variable "color" is assigned to the string form of the first line of the value assigned to the rainbow_messy # variable due to the file method ".readline()". color = rainbow_messy.readline() # In this case, the while loop is followed by the variable "color". Hence, it will evaluate true as long there there # is a value assigned to the color variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the color variable being display in the # output. Subsequently, the color variable will be reassigned to the string form of the next line of the value assigned # to the rainbow_messy variable, due to the file method ".readline()". This loop will continue until the while loop # evaluates false. while color: print(color) color = rainbow_messy.readline()

# [ ] review and run example: strip "*" and newline ('\n') # The variable "rainbow_messy" is assigned to the return file object from using the open() function to open the file named # "rainbow_messy.txt" in read mode, and text mode by default. rainbow_messy = open('rainbow_messy.txt', 'r') # The variable "color" is assigned to the string form of the first line of the value assigned to the rainbow_text # variable due to the file method ".readline()", after the leading and trailing whitespace and the character "*" in the # value assigned to the color variable are removed due to it being attached to the .strip() method. color = rainbow_messy.readline().strip('*\n') # In this case, the while loop is followed by the variable "color". Hence, it will evaluate true as long there there # is a value assigned to the color variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the color variable being display in the # output. Subsequently, the color variable will be reassigned to the string form of the next line of the value assigned # to the rainbow_messy variable, due to the file method ".readline()", after the leading and trailing whitespace and the # character "*" in the value assigned to the color variable are removed due to it being attached to the .strip() method. # This loop will continue until the while loop evaluates false. while color: print(color) color = rainbow_messy.readline().strip('*\n') # This program removes the reference created by the file open() function that is assigned to the rainbow_messy variable, by # using the file method ".close()". rainbow_messy.close()

# [ ] import the file # This program imports a file named "cities_messy.txt" by using the !curl command. !curl https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/cities_messy -o cities_messy.txt

# [ ] run to read the file into memory # The variable "cities_messy" is assigned to the return file object from using the open() function to open the file named # "cities_messy.txt" in read mode, and text mode by default. cities_messy = open('cities_messy.txt', 'r')

# [ ] edit the code to remove leading or trailing colon, newline and space characters # The variable "line" is assigned to the string form of the first line of the value assigned to the cities_messy # variable due to the file method ".readline()", after the leading and trailing whitespace and the character ":" in the # value assigned to the color variable are removed due to it being attached to the .strip() method. line = cities_messy.readline().strip(':\n') # In this case, the while loop is followed by the variable "line". Hence, it will evaluate true as long there there # is a value assigned to the color variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the line variable being display in the # output. Subsequently, the line variable will be reassigned to the string form of the next line of the value assigned # to the cities_messy variable, due to the file method ".readline()", after the leading and trailing whitespace and the # character ":" in the value assigned to the color variable are removed due to it being attached to the .strip() method. # This loop will continue until the while loop evaluates false. while line: print(line) line = cities_messy.readline().strip(':\n') # This program removes the reference created by the file open() function that is assigned to the cities_messy variable, by # using the file method ".close()". cities_messy.close()

# [ ] import https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/poem2_messy as poem2_messy.txt # This program imports a file named "poem2_messy.txt" by using the !curl command. !curl https://raw.githubusercontent.com/MicrosoftLearning/intropython/master/poem2_messy -o poem2_messy.txt

# [ ] open poem2_messy.txt as poem2_messy in read mode # The variable "poem2_messy" is assigned to the return file object from using the open() function to open the file named # "poem2_messy.txt" in read mode, and text mode by default. poem2_messy = open('poem2_messy.txt', 'r')

# [ ] edit while loop to strip the leading and trailing parenthesis, and newlines # [ ] print the poem # The variable "line" is assigned to the string form of the first line of the value assigned to the poem2_messy # variable due to the file method ".readline()", after the leading and trailing whitespace and the characters "(" and ")" # in the value assigned to the poem2_messy variable are removed due to it being attached to the .strip() method. line = poem2_messy.readline().strip("()\n") # In this case, the while loop is followed by the variable "line". Hence, it will evaluate true as long there there # is a value assigned to the color variable. Additionally, the codes that are indented and follow the while loop # will be part of the loop. Thus, the loop starts with the value assigned to the line variable being display in the # output. Subsequently, the line variable will be reassigned to the string form of the next line of the value assigned # to the poem2_messy variable, due to the file method ".readline()", after the leading and trailing whitespace and the # characters "(" and ")" in the value assigned to the color variable are removed due to it being attached to the .strip() # method. This loop will continue until the while loop evaluates false. while line: print(line) line = poem2_messy.readline().strip("()\n") # This program removes the reference created by the file open() function that is assigned to the poem2_messy variable, by # using the file method ".close()". poem2_messy.close()