a)
>>> if rat_1[0] > rat_2[0]: ... print "Rat 1 weighed more than Rat 2 on Day 1." ... else: ... print "Rat 1 weighed less than Rat 2 on Day 1." ...
b)
>>> if rat_1[0] > rat_2[0] and rat_1[-1] > rat_2[-1]: ... print "Rat 1 remained heaver than Rat 2." ... else: ... print "Rat 2 became heavier than Rat 1."
c)
>>> if rat_1[0] > rat_2[0]: ... if rat_1[-1] > rat_2[-1]: ... print "Rat 1 remained heaver than Rat 2." ... else: ... print "Rat 2 became heavier than Rat 1."
You could do it this way:
>>> for i in range(10, 0, -1): ... print i, ... 10 9 8 7 6 5 4 3 2 1
Or this:
>>> i = 10 >>> while i != 0: ... print i, ... i -= 1 ... 10 9 8 7 6 5 4 3 2 1
def remove_neg(num_list): '''Remove the negative numbers from the list num_list.''' i = 0 while i < len(num_list): if num_list[i] < 0: num_list.pop(i) else: i += 1
for i in range(7): blanks = '' ts = '' for j in range(7 - i): blanks += ' ' for j in range(i + 1): ts += 'T' print blanks + ts
a)
rat_1_weight = 10 rat_2_weight = 9 rat_1_rate = 0.04 rat_2_rate = 0.04 rat_1_target = 1.25 + rat_1_weight weeks = 0 while rat_1_weight < rat_1_target: rat_1_weight += rat_1_rate * rat_1_weight weeks += 1 print weeks
b)
rat_1_weight = 10 rat_2_weight = 10 rat_1_rate = 0.07 rat_2_rate = 0.04 weeks = 0 while rat_1_weight < rat_2_weight * 1.10: rat_1_weight += rat_1_rate * rat_1_weight rat_2_weight += rat_2_rate * rat_2_weight weeks += 1 print weeks
a)
import media def swap_pixels(pic, x1, y1, x2, y2): '''Exchange the colors of the pixel (x2, y2) and the color of pixel (x1, y1) in picture pic.''' pixel_1 = media.get_pixel(pic, x1, y1) pixel_2 = media.get_pixel(pic, x2, y2) color_1 = media.get_color(pixel_1) color_2 = media.get_color(pixel_2) media.set_color(pixel_2, color_1) media.set_color(pixel_1, color_2) def mirror(pic): '''Reflect the pixels in Picture pic as if it were held in front of a mirror.''' width = media.get_width(pic) height = media.get_height(pic) middle = width / 2 # Only go halfway so that we don't swap each pair of pixels twice. for x in range(middle): for y in range(height): swap_pixels(pic, x, y, width - 1 - x, y) if __name__ == '__main__': pic = media.load_picture(media.choose_file()) media.show(pic) mirror(pic) media.show(pic)
b)
import media def swap_pixels(pic, x1, y1, x2, y2): '''Exchange the colours of the pixel (x2, y2) and the colour of pixel (x1, y1) in picture pic.''' pixel_1 = media.get_pixel(pic, x1, y1) pixel_2 = media.get_pixel(pic, x2, y2) color_1 = media.get_color(pixel_1) color_2 = media.get_color(pixel_2) media.set_color(pixel_2, color_1) media.set_color(pixel_1, color_2) def mirror(pic): '''Reflect the pixels in Picture pic as if it were held in front of a mirror.''' width = media.get_width(pic) height = media.get_height(pic) middle = height / 2 # Only go halfway so that we don't swap each pair of pixels twice. for x in range(width): for y in range(middle): swap_pixels(pic, x, y, x, height - 1 - y) if __name__ == '__main__': pic = media.load_picture(media.choose_file()) media.show(pic) mirror(pic) media.show(pic)
import media def set_average_square_color(pic, x, y): '''Set the colors of all pixels of the 10 by 10 square with (x, y) as the upper-left corner to the average of the colors of those pixels.''' red_total = 0 green_total = 0 blue_total = 0 for width in range(10): for height in range(10): pixel = media.get_pixel(pic, x + width, y + height) red_total += media.get_red(pixel) green_total += media.get_green(pixel) blue_total += media.get_blue(pixel) red_avg = red_total / 100 green_avg = green_total / 100 blue_avg = blue_total / 100 avg_color = media.Color(red_avg, green_avg, blue_avg) for width in range(10): for height in range(10): pixel = media.get_pixel(pic, x + width, y + height) media.set_color(pixel, avg_color) def mosaic(pic): '''Set the colors of each 10 by 10 block of pixels to the average color of that block.''' x = 0 while x < media.get_width(pic): y = 0 while y < media.get_height(pic): set_average_square_color(pic, x, y) y += 10 x += 10 media.update(pic) if __name__ == '__main__': pic = media.load_picture(media.choose_file()) media.show(pic) mosaic(pic) media.show(pic)