Python内置函数

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1 staticmethod

在类里面把某个函数定义为静态函数,这样对该函数的调用不需要实例化后才能访问,也可以通过 类名.静态函数(args)来调用,比如

class Person:

      @staticmethod

      def static_method():

            print("static_method called")

Person.static_method()

2 str()

用于将值转化为适于人阅读的形式,而repr() 转化为供解释器读取的形式。比如

class Person:

      def __str__(self):

            return "hello"

print( str( {"name": "sysnap", "age": 21} ) )

print( str(p1) )

3 eval()

表达式求值,比如

def amazing(z):

    '''This is the amazing.Helloworld'''

    print("hello amazing", z)

def dump_func(func):

      print("The function named: ", func.__name__)

      print("The function docstring is: n", func.__doc__)

      eval(func.__name__)("test")

dump_func( amazing )

4 super()

调用父类的函数,语法是

class C(B):
    def method(self, arg):
        super(C, self).method(arg)
比如

class Animal(object):

    def __init__(self):

        print("a的构造方法")

        self.a = "动物"

    def hello(self, name):

          print("hello ", name)

  

class Cat(Animal):

    def __init__(self):

        print("b的构造方法")

        self.b = "mao"

        super(Cat, self).__init__()

    def hello(self):

          super(Cat, self).hello("cat")

c1 = Cat()

c1.hello()

5 iter()

迭代器用起来很灵巧,你可以迭代不是序列但表现处序列行为的对象,例如字典的键、一个文件的行,等等

i = iter('abcd')
print i.next()
print i.next()
print i.next()

s = {'one':1,'two':2,'three':3}
print s
m = iter(s)
print m.next()
print m.next()
print m.next()

with open('mydata.txt') as fp:

    for line in iter(fp.readline, ''):

        process_line(line)

原文地址:https://www.cnblogs.com/sysnap/p/6591242.html