• 14、内置函数、递归函数、匿名函数


    一、内置函数

    # print(abs(-1))
    # print(all([1,2,3]))
    # print(all([0,2,3]))

    # print(all(''))

    # print(any([0,None,'',1]))
    # print(any([0,None,'']))
    # print(any([]))

    # print(bin(3))
    # print(hex(17))
    # print(oct(9))

    #0 None 空===》bool值为False,其余都为True

    # def func():
    # pass
    # print(callable(func))


    # print(chr(68))
    # print(ord('D'))


    # res=complex(1+2j)
    # print(res.real)
    # print(res.imag)


    #工厂函数
    # dict
    # int
    # str
    # set
    # list

    # l=[] #l=list([])
    # list([1,2,3])
    # list(['a'])
    # list(['b'])


    # l=[]
    # print(dir(l)) #查看一个对象下面的属性
    #
    # print(help(l))

    # print(divmod(1000,30))

    # x=range(10)
    # enumerate([1,2,3]).__next__()


    # cmd='print("你瞅啥")'

    # dic="{'a':1,'b':2}"
    # d=eval(dic)
    # print(type(d),d['a'])

    # with open('user.db','w',encoding='utf-8') as f:
    # user_dic={'name':'egon','password':'123'}
    # f.write(str(user_dic))

    # with open('user.db','r',encoding='utf-8') as f:
    # dic=f.read()
    # print(dic,type(dic))
    # dic=eval(dic)
    # print(dic['name'])



    s={1,2} #s=set({1,2}) 定义可变集合

    # s.add(3)
    # print(s)

    # s=frozenset({1,2}) # 定义不可变集合


    #哈希:
    # 1. 只要校验的内容一致,那hash得到结果永远一样
    # 2. 不可逆
    # 3. 只要采用的哈希算法一样,那无论被校验的内容有多长,hash的到的结果长度都一样
    # print(hash('asdfasdfsadf'))
    # print(hash('asdfasdfsadf'))

    # x=1
    # y=x
    # print(id(x),id(y))
    #
    # print(x is y) #判断的是身份

    # a=1
    # b=1
    # print(a == b) #判断的是值



    # print(max([1,2,3,4]))

    # print(pow(10,2,3))

    l=['a',4,2,3]
    # for i in reversed(l):
    # print(i)
    #
    # print(list(reversed(l)))

    # i=reversed(l)
    # for x in i:
    # print(x)
    # print(list(i))



    # print(round(3.141542653589127134,4))



    # l=['a','b','c','d','e']
    # print(l[1:4:2])
    # s=slice(1,4,2)
    # print(l[s])


    # vars() #等于locals()


    # s='helloo'
    # l=[1,2,3,4,5]
    #
    # z=zip(s,l)
    # print(z)
    # for i in z:
    # print(i)


    import time


    m=__import__('time') #以字符串的形式导入模块

    # m.sleep(3000)


    #面向对象里面讲
    super

    isinstance
    issubclass


    classmethod
    staticmethod
    property

    delattr
    hasattr
    getattr

    二、递归函数

    #递归调用:在函数调用过程中,直接或间接地调用了函数本身,这就是函数的递归调用


    #
    # def f1():
    # print('from f1')
    # f1()
    #
    # f1()



    # def f1():
    # print('f1')
    # f2()
    #
    # def f2():
    # f1()
    #
    # f1()

    # import sys
    # print(sys.getrecursionlimit())
    # print(sys.setrecursionlimit(1000000))
    #
    # print(sys.getrecursionlimit())



    # age(5)=age(4)+2
    # age(4)=age(3)+2
    # age(3)=age(2)+2
    # age(2)=age(1)+2
    # age(1)=18
    #
    #
    #
    #
    # age(n)=age(n-1)+2 n>1
    # age(n)=18 n=1

    # def age(n):
    # if n == 1:
    # return 18
    # return age(n-1)+2
    #
    # print(age(5))


    #二分法

    l = [1, 2, 10,33,53,71,73,75,77,85,101,201,202,999,11111]

    def search(find_num,seq):
    if len(seq) == 0:
    print('not exists')
    return
    mid_index=len(seq)//2
    mid_num=seq[mid_index]
    print(seq,mid_num)
    if find_num > mid_num:
    #in the right
    seq=seq[mid_index+1:]
    search(find_num,seq)
    elif find_num < mid_num:
    #in the left
    seq=seq[:mid_index]
    search(find_num,seq)
    else:
    print('find it')

    # search(77,l)
    # search(72,l)
    # search(-100000,l)

    三、匿名函数

    # def func(x,y):
    # return x+y
    #
    # func(1,2)


    #匿名函数
    # f=lambda x,y:x+y
    # print(f)
    #
    # print(f(1,2))
    #
    # lambda x,y:x+y


    #max,min,zip,sorted的用法
    salaries={
    'egon':3000,
    'alex':100000000,
    'wupeiqi':10000,
    'yuanhao':2000
    }

    # print(max(salaries))
    # res=zip(salaries.values(),salaries.keys())
    #
    # # print(list(res))
    # print(max(res))

    # def func(k):
    # return salaries[k]

    # print(max(salaries,key=func))
    # print(max(salaries,key=lambda k:salaries[k]))
    # print(min(salaries,key=lambda k:salaries[k]))

    # print(sorted(salaries)) #默认的排序结果是从小到到
    # print(sorted(salaries,key=lambda x:salaries[x])) #默认的排序结果是从小到到
    # print(sorted(salaries,key=lambda x:salaries[x],reverse=True)) #默认的排序结果是从小到到
    #




    # x=1000
    # def f1():
    # # global x
    # x=0
    #
    # f1()
    # print(x)




    '''
    4. 内置函数
    map
    reduce
    filter
    '''


    # def func(f):
    # return f
    #
    # res=func(max)
    # print(res)


    # l=['alex','wupeiqi','yuanhao']
    #
    #
    # res=map(lambda x:x+'_SB',l)
    #
    # print(res)
    #
    # print(list(res))
    #
    # nums=(2,4,9,10)
    #
    # res1=map(lambda x:x**2,nums)
    #
    # print(list(res1))

    # from functools import reduce
    #
    # l=[1,2,3,4,5]
    # print(reduce(lambda x,y:x+y,l,10))


    # l=['alex_SB','wupeiqi_SB','yuanhao_SB','egon']
    #
    # res=filter(lambda x:x.endswith('SB'),l)
    # print(res)
    # print(list(res))












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  • 原文地址:https://www.cnblogs.com/deasion/p/6936652.html
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