72 lines
1.3 KiB
Python
72 lines
1.3 KiB
Python
"""
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对象之间的关联关系
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Version: 0.1
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Author: 骆昊
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Date: 2018-03-12
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"""
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from math import sqrt
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class Point(object):
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def __init__(self, x=0, y=0):
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self._x = x
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self._y = y
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def move_to(self, x, y):
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self._x = x
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self._y = y
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def move_by(self, dx, dy):
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self._x += dx
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self._y += dy
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def distance_to(self, other):
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dx = self._x - other._x
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dy = self._y - other._y
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return sqrt(dx ** 2 + dy ** 2)
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def __str__(self):
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return '(%s, %s)' % (str(self._x), str(self._y))
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class Line(object):
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def __init__(self, start=Point(0, 0), end=Point(0, 0)):
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self._start = start
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self._end = end
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@property
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def start(self):
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return self._start
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@start.setter
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def start(self, start):
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self._start = start
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@property
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def end(self):
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return self.end
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@end.setter
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def end(self, end):
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self._end = end
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@property
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def length(self):
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return self._start.distance_to(self._end)
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if __name__ == '__main__':
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p1 = Point(3, 5)
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print(p1)
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p2 = Point(-2, -1.5)
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print(p2)
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line = Line(p1, p2)
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print(line.length)
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line.start.move_to(2, 1)
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line.end = Point(1, 2)
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print(line.length)
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