改变对象的字符串提示

你想改变对象实例的打印或显示输出,让它们更具有可读性:

class Pair:
  def __init__(self, x, y):
     self.x = x
     self.y = y
  # def __repr__(self):
  #   return 'Pair({0.x!r}, {0.y!r})'.format(self)
  # def __str__(self):
  #   return '({0.x!s}, {0.y!s})'.format(self)
p=Pair('a','b')
print p
print type(p)
print dir(p)


C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/cookbook/a5.py
<__main__.Pair instance at 0x0039BDF0>
<type 'instance'>
['__doc__', '__init__', '__module__', 'x', 'y']



class Pair:
  def __init__(self, x, y):
     self.x = x
     self.y = y
  def __repr__(self):
    return 'Pair({0.x!r}, {0.y!r})'.format(self)
  # def __str__(self):
  #   return '({0.x!s}, {0.y!s})'.format(self)
p=Pair('a','b')
print p
print type(p)
print dir(p)

C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/cookbook/a5.py
Pair('a', 'b')
<type 'instance'>
['__doc__', '__init__', '__module__', '__repr__', 'x', 'y']





class Pair:
  def __init__(self, x, y):
     self.x = x
     self.y = y
  def __repr__(self):
    return 'Pair({0.x!r}, {0.y!r})'.format(self)
  def __str__(self):
    return '({0.x!s}, {0.y!s})'.format(self)
p=Pair('a','b')
print p
print type(p)
print dir(p)


C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/cookbook/a5.py
(a, b)
<type 'instance'>
['__doc__', '__init__', '__module__', '__repr__', '__str__', 'x', 'y']

Process finished with exit code 0