107.html ( File view )

  • By 2010-08-21
  • View(s):12
  • Download(s):0
  • Point(s): 1
			






Safari | Python Developer's Handbook -> Methods Handling





< BACKMake Note | BookmarkCONTINUE >
152015024128143245168232148039199167010047123209178152124239215162147039203230084227186105

Methods Handling

Whenever you have to write methods in your classes, always keep in mind that the namespace searching order for attributes and methods is instance, class, and base classes; and don't forget that self is always the first or only argument to be used in method headers.

Accessing Unbounded Methods

The next example shows what you should do in order to unbind a class method and use it outside the class definition.

						
1: obj = classname()
2: umethod = classname.methodname()
3: umethod(obj, args)

					

Line 1: Creates a class instance object.

Line 2: Creates an object that references the class method. The method is still unattached to the object at this stage.

Line 3: Executes the class method by transporting the instance reference (obj) and the list of arguments (args).

Note that the first argument to an unbound method must be an instance of the correct class, or an exception will be thrown.

Handling Global Class Variables

The next example defines a function that prints a class variable. Every time a new instance is created, Globalcount increases.

						
>>> def printGlobalcount():
     print Globalcount.n

>>> class Couting:
     n = 0
     def __init__(self):
         Globalcount.n = Globalcount.n + 1

>>> inc = Couting()
>>> inc = Couting()
>>> printGlobalcount()
2

					

The next code overwrites the class variable x when subclassing the baseclass class.

						
>>> class baseclass:
     x = 5
     def multiply(self, a):
         return a * (self.__class__.x)

>>> class inherited(baseclass):
     x = 9

>>> x = inherited()
>>> x.multiply(2)
18

					

After a method is defined, it uses the variable values that are associated to the current namespace.

						
>>> class A:
     n = 1
     def printn(self):
         print self.n

>>> class B(A):
     n = 2

>>> class C(B):
     n = 3

>>> obj1 = C()
>>> obj1.printn()
3
>>> obj2 = B()
>>> obj2.printn()
2

					

Calling Methods from Other Methods

The next code exposes how simple it is to create a method to call another method.

						
>>> class c:
     def funcx(self):
         self.funcy()
     def funcy(self):
         print "Ni!"

>>> obj = c()
>>> obj.funcx()
Ni! 

					


Last updated on 1/30/2002
Python Developer's Handbook, © 2002 Sams Publishing

< BACKMake Note | BookmarkCONTINUE >

Index terms contained in this section

accessing
      unbounded method
handling
      methods
methods
      handling
     unbounded
            accessing
object-oriented programming (OOP)
      handling methods
programming
     object-oriented (OOP)
            handling methods
unbounded methods
      accessing

2002, O'Reilly & Associates, Inc.

...
Expand> <Close

Want complete source code? Download it here

Point(s): 1

Download
0 lines left, continue to read
Sponsored links

File list

Tips: You can preview the content of files by clicking file names^_^
Name Size Date
0672319942.html3.37 kB01-06-02 20:06
1.html5.10 kB01-06-02 20:06
10.html3.69 kB01-06-02 20:06
100.html5.41 kB01-06-02 20:06
101.html7.96 kB01-06-02 20:06
102.html3.75 kB01-06-02 20:06
103.html3.75 kB01-06-02 20:06
104.html5.81 kB01-06-02 20:06
105.html16.46 kB01-06-02 20:06
106.html25.87 kB01-06-02 20:06
107.html7.44 kB01-06-02 20:06
108.html20.95 kB01-06-02 20:06
109.html10.02 kB01-06-02 20:06
11.html3.66 kB01-06-02 20:06
110.html9.58 kB01-06-02 20:06
111.html9.96 kB01-06-02 20:06
112.html11.34 kB01-06-02 20:06
113.html7.87 kB01-06-02 20:06
114.html13.56 kB01-06-02 20:06
115.html3.76 kB01-06-02 20:06
116.html3.76 kB01-06-02 20:06
117.html4.27 kB01-06-02 20:06
118.html4.27 kB01-06-02 20:06
119.html9.45 kB01-06-02 20:06
12.html3.66 kB01-06-02 20:06
120.html8.62 kB01-06-02 20:06
121.html65.99 kB01-06-02 20:06
122.html28.42 kB01-06-02 20:06
123.html14.92 kB01-06-02 20:06
124.html7.17 kB01-06-02 20:06
125.html24.21 kB01-06-02 20:06
126.html10.82 kB01-06-02 20:06
127.html10.54 kB01-06-02 20:06
128.html3.86 kB01-06-02 20:06
129.html3.86 kB01-06-02 20:06
13.html12.82 kB01-06-02 20:06
130.html5.85 kB01-06-02 20:06
131.html5.30 kB01-06-02 20:06
132.html29.95 kB01-06-02 20:06
133.html61.54 kB01-06-02 20:06
134.html40.34 kB01-06-02 20:06
135.html9.11 kB01-06-02 20:06
136.html15.53 kB01-06-02 20:06
137.html3.86 kB01-06-02 20:06
138.html3.86 kB01-06-02 20:06
139.html5.80 kB01-06-02 20:06
14.html11.79 kB01-06-02 20:06
140.html14.32 kB01-06-02 20:06
141.html26.46 kB01-06-02 20:06
142.html21.93 kB01-06-02 20:06
143.html17.03 kB01-06-02 20:06
144.html7.95 kB01-06-02 20:06
145.html28.59 kB01-06-02 20:06
146.html52.14 kB01-06-02 20:06
147.html8.37 kB01-06-02 20:06
148.html3.63 kB01-06-02 20:06
149.html3.63 kB01-06-02 20:06
15.html10.93 kB01-06-02 20:06
150.html4.42 kB01-06-02 20:06
151.html16.23 kB01-06-02 20:06
152.html32.55 kB01-06-02 20:06
153.html13.13 kB01-06-02 20:06
154.html28.33 kB01-06-02 20:06
155.html40.15 kB01-06-02 20:06
156.html23.47 kB01-06-02 20:06
157.html7.73 kB01-06-02 20:06
158.html10.61 kB01-06-02 20:06
159.html3.72 kB01-06-02 20:06
16.html11.42 kB01-06-02 20:06
160.html3.72 kB01-06-02 20:06
161.html3.64 kB01-06-02 20:06
162.html3.64 kB01-06-02 20:06
163.html4.70 kB01-06-02 20:06
164.html60.18 kB01-06-02 20:06
165.html42.25 kB01-06-02 20:06
166.html17.91 kB01-06-02 20:06
167.html9.76 kB01-06-02 20:06
168.html13.52 kB01-06-02 20:06
169.html10.35 kB01-06-02 20:06
17.html17.40 kB01-06-02 20:06
170.html9.08 kB01-06-02 20:06
171.html3.61 kB01-06-02 20:06
172.html3.61 kB01-06-02 20:06
173.html6.95 kB01-06-02 20:06
174.html27.86 kB01-06-02 20:06
175.html28.55 kB01-06-02 20:06
176.html16.39 kB01-06-02 20:06
177.html24.60 kB01-06-02 20:06
178.html10.20 kB01-06-02 20:06
179.html3.62 kB01-06-02 20:06
18.html12.04 kB01-06-02 20:06
180.html3.62 kB01-06-02 20:06
181.html7.21 kB01-06-02 20:06
182.html11.83 kB01-06-02 20:06
183.html17.37 kB01-06-02 20:06
184.html87.57 kB01-06-02 20:06
185.html25.23 kB01-06-02 20:06
186.html6.62 kB01-06-02 20:06
187.html3.73 kB01-06-02 20:06
188.html3.73 kB01-06-02 20:06
189.html4.76 kB01-06-02 20:06
19.html5.49 kB01-06-02 20:06
190.html74.34 kB01-06-02 20:06
191.html9.56 kB01-06-02 20:06
192.html31.86 kB01-06-02 20:06
193.html67.73 kB01-06-02 20:06
194.html69.48 kB01-06-02 20:06
195.html32.75 kB01-06-02 20:06
196.html10.74 kB01-06-02 20:06
197.html3.54 kB01-06-02 20:06
198.html3.54 kB01-06-02 20:06
199.html3.81 kB01-06-02 20:06
2.html5.10 kB01-06-02 20:06
20.html9.25 kB01-06-02 20:06
200.html3.81 kB01-06-02 20:06
201.html8.82 kB01-06-02 20:06
202.html7.07 kB01-06-02 20:06
203.html50.32 kB01-06-02 20:06
204.html8.07 kB01-06-02 20:06
205.html7.53 kB01-06-02 20:06
206.html3.60 kB01-06-02 20:06
207.html3.60 kB01-06-02 20:06
208.html7.22 kB01-06-02 20:06
209.html21.63 kB01-06-02 20:06
21.html5.84 kB01-06-02 20:06
210.html24.67 kB01-06-02 20:06
211.html30.17 kB01-06-02 20:06
212.html159.15 kB01-06-02 20:06
213.html18.72 kB01-06-02 20:06
214.html6.54 kB01-06-02 20:06
215.html7.22 kB01-06-02 20:06
216.html6.76 kB01-06-02 20:06
217.html3.11 kB01-06-02 20:06
218.html3.54 kB01-06-02 20:06
219.html4.14 kB01-06-02 20:06
22.html3.69 kB01-06-02 20:06
220.html4.14 kB01-06-02 20:06
221.html4.82 kB01-06-02 20:06
222.html50.92 kB01-06-02 20:06
223.html3.87 kB01-06-02 20:06
224.html57.67 kB01-06-02 20:06
225.html37.66 kB01-06-02 20:06
226.html5.04 kB01-06-02 20:06
227.html3.85 kB01-06-02 20:06
228.html3.85 kB01-06-02 20:06
229.html4.47 kB01-06-02 20:06
23.html3.69 kB01-06-02 20:06
230.html21.41 kB01-06-02 20:06
231.html19.56 kB01-06-02 20:06
232.html26.27 kB01-06-02 20:06
233.html10.07 kB01-06-02 20:06
234.html22.22 kB01-06-02 20:06
235.html36.83 kB01-06-02 20:06
236.html49.23 kB01-06-02 20:06
237.html16.63 kB01-06-02 20:06
238.html6.96 kB01-06-02 20:06
239.html3.09 kB01-06-02 20:06
24.html4.86 kB01-06-02 20:06
240.html3.43 kB01-06-02 20:06
241.html3.59 kB01-06-02 20:06
242.html3.59 kB01-06-02 20:06
243.html17.49 kB01-06-02 20:06
244.html9.38 kB01-06-02 20:06
245.html16.62 kB01-06-02 20:06
246.html9.81 kB01-06-02 20:06
247.html11.50 kB01-06-02 20:06
248.html8.95 kB01-06-02 20:06
249.html8.93 kB01-06-02 20:06
25.html11.48 kB01-06-02 20:06
250.html10.89 kB01-06-02 20:06
251.html8.21 kB01-06-02 20:06
252.html5.14 kB01-06-02 20:06
253.html3.61 kB01-06-02 20:06
254.html3.61 kB01-06-02 20:06
255.html4.61 kB01-06-02 20:06
256.html4.61 kB01-06-02 20:06
257.html43.07 kB01-06-02 20:06
258.html10.12 kB01-06-02 20:06
259.html7.99 kB01-06-02 20:06
26.html25.88 kB01-06-02 20:06
260.html17.17 kB01-06-02 20:06
261.html10.99 kB01-06-02 20:06
262.html15.70 kB01-06-02 20:06
263.html36.19 kB01-06-02 20:06
264.html61.93 kB01-06-02 20:06
265.html39.81 kB01-06-02 20:06
266.html15.13 kB01-06-02 20:06
267.html16.34 kB01-06-02 20:06
268.html3.55 kB01-06-02 20:06
269.html3.55 kB01-06-02 20:06
27.html27.92 kB01-06-02 20:06
270.html14.30 kB01-06-02 20:06
271.html14.21 kB01-06-02 20:06
272.html9.44 kB01-06-02 20:06
273.html8.41 kB01-06-02 20:06
274.html5.45 kB01-06-02 20:06
275.html5.45 kB01-06-02 20:06
276.html8.08 kB01-06-02 20:06
277.html9.78 kB01-06-02 20:06
278.html6.04 kB01-06-02 20:06
279.html6.89 kB01-06-02 20:06
28.html12.02 kB01-06-02 20:06
280.html11.77 kB01-06-02 20:06
281.html10.18 kB01-06-02 20:06
282.html4.98 kB01-06-02 20:06
283.html4.98 kB01-06-02 20:06
284.html4.12 kB01-06-02 20:06
285.html5.78 kB01-06-02 20:06
286.html12.42 kB01-06-02 20:06
287.html6.87 kB01-06-02 20:06
29.html45.69 kB01-06-02 20:06
3.html5.51 kB01-06-02 20:06
30.html10.03 kB01-06-02 20:06
31.html23.06 kB01-06-02 20:06
32.html22.26 kB01-06-02 20:06
33.html18.88 kB01-06-02 20:06
34.html18.25 kB01-06-02 20:06
35.html15.70 kB01-06-02 20:06
36.html5.50 kB01-06-02 20:06
37.html11.83 kB01-06-02 20:06
38.html3.69 kB01-06-02 20:06
39.html3.69 kB01-06-02 20:06
4.html5.51 kB01-06-02 20:06
40.html8.24 kB01-06-02 20:06
41.html12.92 kB01-06-02 20:06
42.html4.51 kB01-06-02 20:06
43.html3.90 kB01-06-02 20:06
44.html3.52 kB01-06-02 20:06
45.html5.99 kB01-06-02 20:06
46.html4.33 kB01-06-02 20:06
47.html4.19 kB01-06-02 20:06
48.html4.01 kB01-06-02 20:06
49.html3.95 kB01-06-02 20:06
5.html4.69 kB01-06-02 20:06
50.html3.63 kB01-06-02 20:06
51.html3.75 kB01-06-02 20:06
52.html5.56 kB01-06-02 20:06
53.html4.41 kB01-06-02 20:06
54.html6.99 kB01-06-02 20:06
55.html3.52 kB01-06-02 20:06
56.html3.95 kB01-06-02 20:06
57.html3.69 kB01-06-02 20:06
58.html4.27 kB01-06-02 20:06
59.html3.88 kB01-06-02 20:06
6.html4.69 kB01-06-02 20:06
60.html3.58 kB01-06-02 20:06
61.html4.17 kB01-06-02 20:06
62.html3.93 kB01-06-02 20:06
63.html3.68 kB01-06-02 20:06
64.html4.16 kB01-06-02 20:06
65.html4.04 kB01-06-02 20:06
66.html4.97 kB01-06-02 20:06
67.html3.91 kB01-06-02 20:06
68.html3.55 kB01-06-02 20:06
69.html3.51 kB01-06-02 20:06
7.html10.67 kB01-06-02 20:06
70.html3.52 kB01-06-02 20:06
71.html3.83 kB01-06-02 20:06
72.html4.02 kB01-06-02 20:06
73.html21.61 kB01-06-02 20:06
74.html12.94 kB01-06-02 20:06
75.html31.26 kB01-06-02 20:06
76.html11.98 kB01-06-02 20:06
77.html4.24 kB01-06-02 20:06
78.html4.26 kB01-06-02 20:06
79.html10.95 kB01-06-02 20:06
8.html10.67 kB01-06-02 20:06
80.html12.11 kB01-06-02 20:06
81.html4.88 kB01-06-02 20:06
82.html6.48 kB01-06-02 20:06
83.html5.64 kB01-06-02 20:06
84.html13.30 kB01-06-02 20:06
85.html7.00 kB01-06-02 20:06
86.html3.90 kB01-06-02 20:06
87.html4.59 kB01-06-02 20:06
88.html5.00 kB01-06-02 20:06
89.html17.71 kB01-06-02 20:06
9.html3.69 kB01-06-02 20:06
90.html6.00 kB01-06-02 20:06
91.html3.68 kB01-06-02 20:06
92.html3.68 kB01-06-02 20:06
93.html12.98 kB01-06-02 20:06
94.html10.60 kB01-06-02 20:06
95.html19.93 kB01-06-02 20:06
96.html10.34 kB01-06-02 20:06
97.html6.27 kB01-06-02 20:06
98.html6.77 kB01-06-02 20:06
99.html16.97 kB01-06-02 20:06
front_matter.html4.16 kB01-06-02 20:06
index.html3.37 kB01-06-02 20:06
new_toc.html15.79 kB01-06-02 20:06
rindex1.html53.02 kB01-06-02 20:05
rindex10.html5.16 kB01-06-02 20:05
rindex11.html3.96 kB01-06-02 20:05
rindex12.html15.07 kB01-06-02 20:05
rindex13.html84.43 kB01-06-02 20:05
rindex14.html10.85 kB01-06-02 20:05
rindex15.html26.04 kB01-06-02 20:05
rindex16.html58.33 kB01-06-02 20:05
rindex17.html3.52 kB01-06-02 20:05
rindex18.html16.83 kB01-06-02 20:05
rindex19.html52.89 kB01-06-02 20:05
rindex2.html13.47 kB01-06-02 20:05
rindex20.html17.55 kB01-06-02 20:05
rindex21.html13.56 kB01-06-02 20:05
rindex22.html10.63 kB01-06-02 20:05
rindex23.html16.92 kB01-06-02 20:05
rindex24.html4.90 kB01-06-02 20:05
rindex25.html2.50 kB01-06-02 20:05
rindex3.html43.59 kB01-06-02 20:06
rindex4.html21.76 kB01-06-02 20:06
rindex5.html22.31 kB01-06-02 20:06
rindex6.html36.57 kB01-06-02 20:06
rindex7.html14.06 kB01-06-02 20:06
rindex8.html11.93 kB01-06-02 20:06
rindex9.html25.33 kB01-06-02 20:06
toc.html24.97 kB01-06-02 20:06
<(ebook>0.00 BPython) O'Reilly
<0672319942>0.00 B25-08-02 17:24
<graphics>0.00 B25-08-02 17:24
<images>0.00 B25-08-02 17:24
<oreillyi>0.00 B25-08-02 17:24
oreillyM.css4.42 kB31-05-02 17:16
oreillyN.css4.42 kB31-05-02 17:16
00.gif41.00 B31-05-02 17:16
01fig01.gif58.03 kB28-01-02 08:54
01fig02.gif39.76 kB28-01-02 08:54
01fig03.gif22.06 kB28-01-02 08:54
01fig04.gif64.75 kB28-01-02 08:54
02fig01.gif54.48 kB28-01-02 08:54
02fig02.gif16.29 kB28-01-02 08:54
02fig03.gif14.11 kB28-01-02 08:54
02fig04.gif47.82 kB28-01-02 08:54
06fig01.gif32.19 kB28-01-02 08:54
06fig02.gif58.39 kB28-01-02 08:54
06fig03.gif48.96 kB28-01-02 08:54
07fig01.gif47.96 kB28-01-02 08:54
07fig02.gif8.99 kB28-01-02 08:54
07fig03.gif9.46 kB28-01-02 08:54
07fig04.gif11.51 kB28-01-02 08:54
07fig05.gif8.27 kB28-01-02 08:54
07fig06.gif31.46 kB28-01-02 08:54
12fig01.gif34.54 kB28-01-02 08:54
15fig01.gif1.30 kB28-01-02 08:54
15fig02.gif1.50 kB28-01-02 08:54
15fig03.gif5.93 kB28-01-02 08:54
15fig04.gif924.00 B28-01-02 08:54
15fig05.gif1.55 kB28-01-02 08:54
15fig06.gif1.62 kB28-01-02 08:54
15fig07.gif1.69 kB28-01-02 08:54
15fig08.gif1.02 kB28-01-02 08:54
15fig09.gif2.54 kB28-01-02 08:54
15fig10.gif1.92 kB28-01-02 08:54
15fig11.gif2.44 kB28-01-02 08:54
15fig12.gif2.48 kB28-01-02 08:54
15fig13.gif2.36 kB28-01-02 08:54
15fig14.gif5.43 kB28-01-02 08:54
15fig15.gif5.51 kB28-01-02 08:54
15fig16.gif2.18 kB28-01-02 08:54
15fig17.gif12.22 kB28-01-02 08:54
16fig01.gif28.99 kB28-01-02 08:54
16fig02.gif23.02 kB28-01-02 08:54
16fig03.gif32.48 kB28-01-02 08:54
16fig04.gif17.27 kB28-01-02 08:54
16fig05.gif23.88 kB28-01-02 08:54
16fig06.gif23.85 kB28-01-02 08:54
16fig07.gif36.76 kB28-01-02 08:54
16fig08.gif20.66 kB28-01-02 08:54
16fig09.gif71.63 kB28-01-02 08:54
16fig10.gif23.23 kB28-01-02 08:54
16fig11.gif22.97 kB28-01-02 08:54
16fig12.gif22.06 kB28-01-02 08:54
16fig13.gif49.73 kB28-01-02 08:54
16fig14.gif60.34 kB28-01-02 08:54
18fig01.gif63.94 kB28-01-02 08:54
18fig02.gif24.07 kB28-01-02 08:54
ccc.gif109.00 B28-01-02 08:54
spacer.gif41.00 B31-05-02 17:16
view.gif41.00 B31-05-02 17:16
0672319942_s.jpg2.91 kB29-01-02 11:29
...
Sponsored links

107.html (1.65 MB)

Need 1 point
Your Point(s)

Your Point isn't enough.

Get point immediately by PayPal

More(Debit card / Credit card / PayPal Credit / Online Banking)

Submit your source codes. Get more point

LOGIN

Don't have an account? Register now
Need any help?
Mail to: support@codeforge.com

切换到中文版?

CodeForge Chinese Version
CodeForge English Version

Where are you going?

^_^"Oops ...

Sorry!This guy is mysterious, its blog hasn't been opened, try another, please!
OK

Warm tip!

CodeForge to FavoriteFavorite by Ctrl+D