CSC111 Exercises with Lists

--D. Thiebaut (talk) 09:53, 24 March 2014 (EDT)

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Exercise 1

Question 1

Create a list with all the odd numbers between 1 and 100.

Question 2

Create a list with all the odd numbers less than 10,000,000

Figure out a way to print the list in an efficient and elegant way

Exercise 2

Question 1

Split a line of text into a list of words.

Question 2

Reformat the list of words as a string with the |-character as separator instead of a space

Exercise 3

Question 1

Given the text in the first list of this page which represents lists of media files, create a list of just the names of the files.

Question 2

Given the list on the same page, find the file that takes the most amount of disk space.

Question 3

List the files as a name followed by a size, one per line

Question 4

Same as Question 3, but sort the list alphabetically

Question 5

Same as Question 3, but sort the list by file size

Question 6

Create a new list that contains only the size, month, day, year and file name for each file. In other words, drop the first 4 fields of each line.

Solution Program

videoFiles.py

text = """-rw-r--r--  1 thiebaut  staff   31512938 Jan 21 19:10 ComputerScienceAnalytics_6.mp4
-rw-r--r--  1 thiebaut  staff   36326928 Feb 21 19:10 ComputerScienceAnalytics_7.mp4
-rw-r--r--  1 thiebaut  staff   25889113 Feb 21 19:06 ComputerScienceAnalytics_8.mp4
-rw-r--r--  1 thiebaut  staff   23700210 Jan 17 19:08 ComputerScienceAnalytics_9.mp4
-rw-r--r--  1 thiebaut  staff   45115774 Jan 13 19:13 ComputerScienceFinancialApplications_Plank_01.mp4
-rw-r--r--  1 thiebaut  staff   36406334 Dec 16 13:42 ComputerScienceFinancialApplications_Plank_02.mp4
-rw-r--r--  1 thiebaut  staff   46622104 Dec 16 19:10 ComputerScienceFinancialApplications_Plank_03.mp4
-rw-r--r--  1 thiebaut  staff   53252084 Jan 17 19:11 ComputerScienceFinancialApplications_Plank_04.mp4
-rw-r--r--  1 thiebaut  staff   45092698 Jan 21 13:46 ComputerScienceFinancialApplications_Plank_05.mp4
-rw-r--r--  1 thiebaut  staff   61646571 Dec 30 19:11 ComputerScienceFinancialApplications_Plank_06.mp4
-rw-r--r--  1 thiebaut  staff   59283490 Jan 21 13:48 ComputerScienceMedicine_Monvieux_01.mp4
-rw-r--r--  1 thiebaut  staff   76205259 Jan 31 13:42 ComputerScienceMedicine_Monvieux_02.mp4
-rw-r--r--  1 thiebaut  staff   72940315 Dec 17 20:04 ComputerScienceMedicine_Monvieux_03.mp4
-rw-r--r--  1 thiebaut  staff   48119432 Dec 31 19:14 ComputerScienceMedicine_Monvieux_04.mp4
-rw-r--r--  1 thiebaut  staff  100468403 Dec 16 19:26 ComputerScienceMedicine_Monvieux_05.mp4
-rw-r--r--  1 thiebaut  staff  100468403 Dec 16 19:26 ComputerScienceMedicine_Monvieux_06.mp4
-rw-r--r--  1 thiebaut  staff   63308062 Dec 16 13:46 ComputerScienceMedicine_Monvieux_07.mp4
-rw-r--r--  1 thiebaut  staff   57665921 Dec 30 19:09 ComputerScienceSystemsScalability_Zardoz_1.mp4
-rw-r--r--  1 thiebaut  staff   84255667 Jan 17 19:13 ComputerScienceSystemsScalability_Zardoz_2.mp4
-rw-r--r--  1 thiebaut  staff   91981675 Jan 17 19:13 ComputerScienceSystemsScalability_Zardoz_3.mp4
-rw-r--r--  1 thiebaut  staff   53601252 Dec 16 19:12 ComputerScienceSystemsScalability_Zardoz_4.mp4
-rw-r--r--  1 thiebaut  staff   61131921 Jan 21 13:46 AnalyticsFastAlgorithms_Lowenthal_1.mp4
-rw-r--r--  1 thiebaut  staff   42672117 Jan 21 13:46 AnalyticsFastAlgorithms_Lowenthal_2.mp4
-rw-r--r--  1 thiebaut  staff   31806559 Jan 15 16:23 AnalyticsFastAlgorithms_Lowenthal_3.mp4
-rw-r--r--  1 thiebaut  staff   43803673 Jan 15 16:24 AnalyticsFastAlgorithms_Lowenthal_4.mp4
-rw-r--r--  1 thiebaut  staff   37293159 Jan 15 19:09 AnalyticsFastAlgorithms_Lowenthal_5.mp4
-rw-r--r--  1 thiebaut  staff   46556009 Jan 29 19:12 AnalyticsFastAlgorithms_Lowenthal_6.mp4
-rw-r--r--  1 thiebaut  staff   38307419 Jan 29 19:10 AnalyticsFastAlgorithms_Lowenthal_7.mp4
-rw-r--r--  1 thiebaut  staff   41391629 Feb 21 13:34 ComputerScienceAnalytics_1.mp4
-rw-r--r--  1 thiebaut  staff   56999320 Feb 21 19:11 ComputerScienceAnalytics_2.mp4
-rw-r--r--  1 thiebaut  staff   48847747 Jan 21 13:50 ComputerScienceAnalytics_3.mp4
-rw-r--r--  1 thiebaut  staff   21625121 Feb 21 19:06 ComputerScienceAnalytics_4.mp4
-rw-r--r--  1 thiebaut  staff   26003908 Jan 23 13:43 ComputerScienceAnalytics_5.mp4

"""

ListExercises.py

# ListExercises.py
# D. Thiebaut
# answers to Exercises given in
# http://cs.smith.edu/dftwiki/index.php/CSC111_Exercises_with_Lists
# 
from videoFiles import text


# box(): prints a caption inside a box
def box( caption ):
    length = len( caption )+2
    print( "\n\n\n+" + "-"*length + "+" )
    print( "| " + caption  + " |" )
    print( "+" + "-"*length + "+" )

# answer to Exercise 1
def exo1():
    box( "Exercise 1" )
    list = []
    for i in range( 1, 100, 2 ):
        list.append( i )

    print( "list = ", list )

    list = []
    for i in range( 1, 10000000, 2 ):
        list.append( i )
    print( "list = ", list[0],"...", list[-1] )
    
# answer to Exercise 2
def exo2():
    box( "Exercise 2" )
    line = "The quick red fox jumped over the brown sleeping dog"
    words = line.split()
    print( "words = ", words )
    separator = "|"
    newLine = separator.join( words )
    print( "newLine = ", newLine )

# answer to Exercise 3
def exo3():
    # Question 1
    box( "Exercise 3, Question 1" )
    list = []
    for line in text.split( "\n" ):
        if len( line ) <= 1:
            continue
        words = line.split()
        list.append( words[-1] )

    print( "list = ", "\n".join( list ) )

    # Question 2
    box( "Exercise 3, Question 2" )
    max     = 0
    fileMax = ""
    for line in text.split( "\n" ):
        if len( line ) <= 1:
            continue
        words = line.split()
        size = int( words[4] )
        if size > max:
            max = size
            fileMax = words[-1]

    print( "Largest file = %s (%d bytes)" % (fileMax, max) )

    # Question 3
    box( "Exercise 3, Question 3" )
    for line in text.split( "\n" ):
        if len( line ) <= 1:
            continue
        words  = line.split()
        print( "%50s %10d" % ( words[-1], int(words[4])) )
    
    # Question 5
    box( "Exercise 3, Question 4" )
    newList = []
    for line in text.split( "\n" ):
        if len( line ) <= 1:
              continue
        words = line.split()
        pair = ( words[-1], words[4] )
        newList.append( pair )

    newList.sort()
    for name, size in newList:
         print( name, size )

def main():
    #exo1()
    #exo2()
    exo3()
    
main()