# 쿼리 문자열: 'red=5&blue=0&green='
red = my_values.get('red', [''])[0] or 0
green = my_values.get('green', [''])[0] or 0
opacity = my_values.get('opacity', [''])[0] or 0
print('Red:     %r' % red)
print('Green:   %r' % green)
print('Opacity: %r' % opacity)

>>> 
Red:     '5'
Green:   0
Opacity: 0
