函数可带返回操作(return)。该操作终止并退出函数;同行,它往往会带一些返回值。(没有具体返回值则返回None。) 我们打开IDLE对话模式,直接带定义一个函数。 >>> def conf_intf(inf,ip,mask): ... print('intface',inf) ... print('ip address',ip,mask) ... >>> 这样,我们就完成了一个函数conf_int...
Functions that you write can also call other functions you write. It is a good convention to have the main action of a program be in a function for easy reference. The example programbirthday5.pyhas the two Happy Birthday calls inside a final function,main. Do you see that this version ...
Return语句用来退出函数并将程序返回到函数调用的位置继续执行。Return语句可以同时将多个函数运算后的结果返回给函数被调用的变量。没有return，此时函数就不返回值。The Return statement is used to exit the function and return the program to the location of the function call to continue execution. A Return ...
All Python functions have a return value, either explicit or implicit. You’ll cover the difference between explicit and implicit return values later in this tutorial. To write a Python function, you need a header that starts with the def keyword, followed by the name of the function, an ...
To express certain general patterns as named concepts, we will need to construct functions that canaccept other functions as arguments or return functions as values. 1.6.1 Functions as Arguments 三个例子: defsum_naturals(n): total, k =0,1whilek <= n: ...
Coming from other languages, you might object that fib is not a function but a procedure since it doesn’t return a value. In fact, even functions without a return statement do return a value, albeit a rather boring one. This value is called None (it’s a built-in name). Writing the...
1#使用装饰器(decorator),2#这是一种更pythonic,更elegant的方法,3#单例类本身根本不知道自己是单例的,因为他本身(自己的代码)并不是单例的4defsingleton(cls,*args,**kw):5instances={}6def_singleton():7ifcls notininstances:8instances[cls]=cls(*args,**kw)9returninstances[cls]10return_singleton11...
Item 19: Never Unpack More Than Three Variables When Functions Return Multiple Values Unpacking into four or more variables is error prone and should be avoided; instead, return a small class or namedtuple instance. Item 22: Reduce Visual Noise with Variable Positional Arguments ...
>>> record = json.loads(frame.T.to_json()).values() >>> record dict_values([{'white': 0, 'red': 1, 'blue': 2, 'black': 3, 'green': 4}, {'white': 5, 'red': 6, 'blue': 7, 'black': 8, 'green': 9}, {'white': 10, 'red': 11, 'blue': 12, 'black':...
)方法遍历输出值 for value in menu.values(): print(food_price:'+value) 输出结果 food_price:40 food_price:30food_price:20 food_price:50 输出结果表示,values()方法每次都是将menu菜单中的值输出,显示菜的价格 如果您想了解更多有关字典使用知识,请参考:【美】Eric Matthes著《Python——从入门...