Question

我正在写一个类，Tbeam（IPython笔记本2.2.0中的Python 2.7.8），它计算钢筋混凝土T梁的值。 Tbeam的凸缘和腹板被认为是Rectangle类的对象。我从类Tbeam中的类Rectangle实例化一个法兰和web，并创建方法来计算Tbeam的整体深度（d）和面积（面积）。

class Rectangle:
"""A class to create simple rectangle with dimensions width (b) and 
height (d). """

def __init__(self, b, d ):
    """Return a rectangle object whose name is *name* and default
    dimensions are width = 1, height = 1.
    """
    self.width = b
    self.height = d

def area(self):
    """Computes the area of a rectangle"""
    return self.width * self.height

def inertia(self):
    """Computes the moment of inertia of a rectangle,
    with respect to the centroid."""

    return self.width*math.pow(self.height,3)/12.0

def perim(self):
    """Calculates the perimeter of a rectangle"""
    return 2*(self.width+self.height)

def centroid(self):
    """Calculates the centroid of a rectangle"""
    return self.height/2.0

def d(self):
    """Returns the height of the rectangle."""
    return self.height

def bf(self):
    """Returns the width of the rectangle."""
    return self.width

-

class Tbeam:

"""A class to create T beams with dimensions:
bf = width of top flange,
tf = thickness of top flange,
d = height of web,
bw = width of web. """

def __init__(self, bf,tf,d,bw):
    self.bf = bf
    self.tf = tf
    self.d = d
    self.bw = bw
    self.flange = Rectangle(bf,tf)
    self.web = Rectangle(bw,d)

def area(self):
    area =self.flange.area + self.web.area

def d(self):
    """Returns the total height of the Tbeam"""
    return self.flange.d + self.web.d

-

执行测试单元时

# Test Tbeam
t1 = Tbeam(60.0, 5.0,27.0,12.0)
print t1.d
print t1.area

-

我得到以下内容：

27.0

bound method Tbeam.area of <__main__.Tbeam instance at 0x7f8888478758

27.0是正确的，但我不明白打印t1.area的第二个响应。我认为我对区域的定义是不正确的，但我不知道如何纠正这个问题。

非常感谢

罗恩

Answer 1

您正在打印t1.area这是一种方法。您想打印调用方法的结果，因此print t1.area()。

Answer 2

面积方法定义为

def area(self):
    area =self.flange.area + self.web.area

但应定义为

def area(self):
    area =self.flange.area() + self.web.area()

python 2.7在另一个类中实例化类

2 个答案: