跟黃哥學python序列文章之python方法鏈(method chaining)

寫這篇文章來由，有朋友說下面這樣的代碼看不懂。

choice = raw_input("please input:n").strip()[0].lower()

這個其實是面向對象中方法鏈的概念。

請看維基百科上Method chaining的定義

Method chaining, also known as named parameter idiom, n is a common syntax for invoking multiple method calls n in object-oriented programming languages.n Each method returns an object, allowing the calls n to be chained together in a single statement without requiring n variables to store the intermediate results.n Local variable declarations are syntactic n sugar because of the difficulty humans have with deeply nested method calls.n A method chain is also known as a train wreck due to the increase n in the number of methods that come one after another in the same n line that occurs as more methods are chained togethern even though line breaks are often added between methods.n

具體在python中，請看黃哥的分析：

有的python初學者對python方法連續調用不是很清楚，像霧裡看花一樣。npython一切都是對象，對象調用它的方法，如果帶返回值，返回值也是對象， n這個返回值也有方法，當然就可以用點號調用它的方法， n如此下去，就是python方法鏈調用也。n

如何設計方法鏈python代碼

# coding:utf-8n"""n如何通過學習python學會編程nhttps://github.com/pythonpeixun/article/blob/master/python/how_to_learn_python.mdn黃哥python遠程視頻培訓班nhttps://github.com/pythonpeixun/article/blob/master/index.mdn黃哥python培訓試看視頻播放地址nhttps://github.com/pythonpeixun/article/blob/master/python_shiping.mdn黃哥python培訓 諮詢qq:1465376564n"""nnnclass Person(object):n """方法鏈小sample"""nn def name(self, value):n self.name = valuen return self # 返回實例對象自己才能再調用實例對象的方法。nn def work(self, value):n self.working = valuen return selfnn def introduce(self):n print "你好, 我的名字:", self.name, ",我的工作:", self.working, ",教初學者學會編程!"nnperson = Person()nperson.name("黃哥").work("黃哥python培訓").introduce()n

php方法鏈代碼

<?phpn /*n 黃哥php培訓 諮詢qq:1465376564n https://github.com/pythonpeixun/article/blob/master/php_education.mdn */nnn class Person{n public $name;n public $working;nn public function setName($value){n $this->name = $value;n return $this;n }nn public function work($value){n $this->working = $value;n return $this;n }nn public function introduce(){n echo "你好, 我的名字:".$this->name.",我的工作:".$this->working.",教初學者學會編程!n";n }n }nn $person = new Person();n $person->setName("黃哥")->work("黃哥php培訓")->introduce();n

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