CSC111 Lab 13 2015

--D. Thiebaut (talk) 09:59, 27 April 2015 (EDT)

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This lab is a preparation for the Final Exam. You will notice that the amount of explanations is limited, and you are asked to start from scratch writing a program. The lab will start with a general discussion about approaching the problems, and getting started with such assignments.
Feel free to work in pair programming mode on this assignment.

Problem 1

Write a graphics program that uses a white background, and makes a fish appear wherever the user clicks the mouse. Once the fish appears on the screen it moves slowly to one side and disappears. While the fish is moving, the user may click on the screen, and make other fish appear. The new fish will then move at the same pace as the first fish, assuming it is still visible.

Problem 2

The file at URL http://cs.smith.edu/dftwiki/media/1000movies.txt contains the list of the best 1000 movies of all times, according to The New York Times.
Write a program that will:

1. Ask the user for the year she was born in, e.g. 1995,
2. Read the contents of the file at the URL specified above
3. Find all the movies that were released in the year specified by the user
4. Output the movies sorted by alphabetical order. The year (or parentheses around the year) should not appear in the lines listing the movie titles.
5. Save the list to a file called movies1995.txt (replace 1995 by whatever number the user specified as year).

There is nothing to submit to Moodle this week. Just concentrate on making sure you get working versions of the solution programs for this lab.

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Program 1

# lab13_1.py
# D. Thiebaut
# Graphics program that puts fish wherever the user
# clicks on the window.   The fish wrap around when they go
# off the window, although this was not a required feature in
# the lab.
# The program stops when the user clicks close to the top-left
# corner of the window (within 20 pixels of the point 0,0).
from graphics import *
import random

WIDTH = 800
HEIGHT = 600

class Fish:
    """A class that represents a fish, with an image."""
    
    def __init__( self, refP ):
        """constructs the fish with an image"""
        self.image = Image( refP, "fish10.gif" )
    
    def draw( self, win ):
        """draws the fish on the window..."""
        self.image.draw( win )

    def autoMove( self ):
        """make the fish move to the right, some random distance"""
        self.image.move( random.randrange( 4 ), 0 )
        if self.image.getAnchor().getX() > WIDTH+50:
            self.image.move( -WIDTH-100, 0 )

def isInCorner( p ):
    """Returns True if the point p is within 20 pixels of the top left
    corner of the window, and False otherwise."""
    if p.getX() < 20 and p.getY() < 20:
        return True
    return False
        
def main():
    win = GraphWin( "Lab 13", WIDTH, HEIGHT )

    # get ready to add fish...
    fishList = []
    
    #animation loop
    while True:
        p = win.checkMouse()

        # user clicked the mouse...
        if p != None:

            # is it in the upper-left corner?
            if isInCorner( p ):
                break

            fish = Fish( p )
            fish.draw( win )
            fishList.append( fish )

        # move all the fish, a tiny bit...
        for fish in fishList:
            fish.autoMove()

    win.close()

main()

Program 2

import urllib.request  # the lib that handles the url stuff

url = "http://cs.smith.edu/dftwiki/media/1000movies.txt"


def getText( url ):
    """gets the contents of the text file at the given URL"""
    # fetch the file and put its contents in the
    # string text.
    response = urllib.request.urlopen( url )
    text     = response.read().decode( 'UTF-8' )
    return text

def saveToFile( fileName, text ):
    """save the text into the given file """
    file = open( fileName, "w" )
    file.write( text + "\n" )
    file.close()
    
def main():
    """retrieve the file at the given URL, gets a year
    from the user, and outputs all the lines containing that
    given year.  The output is also saved to a file."""
    text = getText( url )

    year = input( "Year you were born? " ).strip()

    list = []
    for line in text.split( "\n" ):
        if line.find( year ) != -1:
            index = line.find( "(" + year )
            line = line[0:index].strip()
            print( line )
            list.append( line )

    saveToFile( "movies"+year+".txt", "\n".join( list ) )


main()