python编程---example4

## one
# alien_o = {'color':'green','points':5}
# new_points = alien_o['points']
# print("You just earned " + str(new_points) + " points!")

## two
# alien_o = {'color':'green','points':5}
# print(alien_o)
# 
# alien_o['x_position'] = 0
# alien_o['y_position'] = 25
# print(alien_o)

## 1
# alien_o = {}
# alien_o['color'] = 'green'
# alien_o['points'] = 5
# print(alien_o)

## 2
# alien_o = {'color':'green'}
# print("The alien is " + alien_o['color'] + ".")
# 
# alien_o['color'] = 'yellow'
# print("The alien is " + alien_o['color'] + ".")

## 3
alien_o = {'x_position':0, 'y_position':25, 'speed':'medium'}
print("Original x-position: " + str(alien_o['x_position']))

alien_o['speed'] = 'fast'

if alien_o['speed'] == 'slow':
	x_increment = 1
elif alien_o['speed'] == 'medium':
	x_increment = 2
elif alien_o['speed'] == 'fast':
	x_increment = 3

alien_o['x_position'] = alien_o['x_position'] + x_increment
print("New x-position: " + str(alien_o['x_position']))

## three
# alien_0 = {'color':'green','points':'5'}
# alien_1 = {'color':'yellow','points':'10'}
# alien_2 = {'color':'red','points':'15'}
# 
# aliens = [alien_0,alien_1,alien_2]
# 
# for alien in aliens:
# 	print(alien)
# print(aliens)

## four
# create alien
# aliens = []
# 
# for alien_number in range(30):
# 	if alien_number < 10:
# 		new_alien = {'color':'green','points':'5','speed':'slow'}
# 		aliens.append(new_alien)
# 	elif alien_number < 20:
# 		new_alien = {'color':'yellow','points':'10','speed':'medium'}
# 		aliens.append(new_alien)
# 	elif alien_number < 30:
# 		new_alien = {'color':'red','points':'15','speed':'fast'}
# 		aliens.append(new_alien)
# 
# for alien in aliens:
# 	print(alien)
# 
# print("Total number of aliens: " + str(len(aliens)))

## five
## create alien
# aliens = []
# 
# for alien_number in range(30):
# 	new_alien = {'color':'green','points':'5','speed':'slow'}
# 	aliens.append(new_alien)
# 
# for alien in aliens[0:5]:
# 	if alien['color'] == 'green':
# 		alien['color'] = 'yellow'
# 		alien['points'] = 10
# 		alien['speed'] = 'medium'
# 	elif alien['color'] == 'yellow':
# 		alien['color'] = 'red'
# 		alien['points'] = 15
# 		alien['speed'] = 'fast'
# 
# for alien in aliens[:]:
# 	print(alien)
# 
# print('...\n')
# print(aliens)