# write a function
# to read students.txt file
# for each line, add student's email address, separated by comma
# using the following format
#     name,email
# then, write the students' information (name,address) to
# another file named studentinfo.txt
#
# Download: students.txt

def inclass():
    infile = open('students.txt','r')

    # if the file does not exist, create one and set it to be writable
    outfile = open('studentinfo.txt', 'w')

    line = infile.readline()
    string1 = ''
    while line != '':
        name = line.rstrip('\n')
        string1 = string1 + name + ',' + name + '@virginia.edu' + '\n'

        line = infile.readline()  # what happen if this line is commented out

    print(string1)
    outfile.write(string1)

    # close the file
    infile.close()
    outfile.close()






def write_file():
    # open a file named students.txt
    outfile = open('students.txt', 'w')

    # write the names of three students to the file
    outfile.write('John\n')
    outfile.write('Jack\n')
    outfile.write('Jane\n')

    # close the file
    outfile.close()





def append_file():
    # open a file named students.txt
    outfile = open('students.txt', 'a')

    # append another student's name to the file
    outfile.write('Mary\n')

    # close the file
    outfile.close()


def readline_file():
    # open a file named students.txt to be read
    infile = open('students.txt', 'r')

    # read 2 lines from the file
    line1 = infile.readline()
    line2 = infile.readline()

    print("---- readline_file() ----")
    # notice the differences how the following statements print

    print(line1)
    print(line2)
    print(line1, line2)

    # now, let's try formatting the lines
    # by stripping the \n from each string
    line1 = line1.strip('\n')    # remove from left and right
    line2 = line2.rstrip('\n')   # remove from right end
    print(line1)
    print(line2)
    print(line1, line2)

    # close the file
    infile.close()




def readline_file_with_loop():
    # open a file named students.txt to be read
    infile = open('students.txt', 'r')

    line = infile.readline()
    print("---- readline_file_with_loops ----")
    while line != '':
        print(line.rstrip('\n'))
        line = infile.readline()       # what happen if this line is commented out

    # close the file
    infile.close()



def read_file():
    # open a file named students.txt to be read
    infile = open('students.txt', 'r')

    # read the file's contents
    file_contents = infile.read()

    print("---- read_file() ----")
    print(file_contents)

    # close the file
    infile.close()



write_file()
append_file()
readline_file()
readline_file_with_loop()
read_file()
inclass()


# Q: Where is the student.txt file ? What does it look like?