设为首页收藏本站
查看: 50|回复: 0

[PHP] Python常用知识点

[复制链接]

论坛元老

Rank: 6Rank: 6

积分
34274
主题
17031
UID
1347
M币
67
贡献
17176

  • 发表于 2017-5-14 02:44:00 | 显示全部楼层 |阅读模式
    1、Set基本数据类型
    a、set集合,是一个无序且不重复的元素集合
    class set(object): """ set() -> new empty set object set(iterable) -> new set object Build an unordered collection of unique elements. """ def add(self, *args, **kwargs): # real signature unknown """ Add an element to a set,添加元素 This has no effect if the element is already present. """ pass def clear(self, *args, **kwargs): # real signature unknown """ Remove all elements from this set. 清楚内容""" pass def copy(self, *args, **kwargs): # real signature unknown """ Return a shallow copy of a set. 浅拷贝 """ pass def difference(self, *args, **kwargs): # real signature unknown """ Return the difference of two or more sets as a new set. A中存在,B中不存在 (i.e. all elements that are in this set but not the others.) """ pass def difference_update(self, *args, **kwargs): # real signature unknown """ Remove all elements of another set from this set. 从当前集合中删除和B中相同的元素""" pass def discard(self, *args, **kwargs): # real signature unknown """ Remove an element from a set if it is a member. If the element is not a member, do nothing. 移除指定元素,不存在不保错 """ pass def intersection(self, *args, **kwargs): # real signature unknown """ Return the intersection of two sets as a new set. 交集 (i.e. all elements that are in both sets.) """ pass def intersection_update(self, *args, **kwargs): # real signature unknown """ Update a set with the intersection of itself and another. 取交集并更更新到A中 """ pass def isdisjoint(self, *args, **kwargs): # real signature unknown """ Return True if two sets have a null intersection. 如果没有交集,返回True,否则返回False""" pass def issubset(self, *args, **kwargs): # real signature unknown """ Report whether another set contains this set. 是否是子序列""" pass def issuperset(self, *args, **kwargs): # real signature unknown """ Report whether this set contains another set. 是否是父序列""" pass def pop(self, *args, **kwargs): # real signature unknown """ Remove and return an arbitrary set element. Raises KeyError if the set is empty. 移除元素 """ pass def remove(self, *args, **kwargs): # real signature unknown """ Remove an element from a set; it must be a member. If the element is not a member, raise a KeyError. 移除指定元素,不存在保错 """ pass def symmetric_difference(self, *args, **kwargs): # real signature unknown """ Return the symmetric difference of two sets as a new set. 对称交集 (i.e. all elements that are in exactly one of the sets.) """ pass def symmetric_difference_update(self, *args, **kwargs): # real signature unknown """ Update a set with the symmetric difference of itself and another. 对称交集,并更新到a中 """ pass def union(self, *args, **kwargs): # real signature unknown """ Return the union of sets as a new set. 并集 (i.e. all elements that are in either set.) """ pass def update(self, *args, **kwargs): # real signature unknown """ Update a set with the union of itself and others. 更新 """ pass
    b、数据类型模块举例
    se = {11,22,33,44,55} be = {44,55,66,77,88} # se.add(66) # print(se) #添加元素,不能直接打印! # # # # se.clear() # print(se) #清除se集合里面所有的值,不能清除单个 # # # # ce=be.difference(se) #se中存在,be中不存在的值,必须赋值给一个新的变量 # print(ce) # # # se.difference_update(be) # print(se) #在se中删除和be相同的值,不能赋值给一个新的变量,先输入转换,然后打印,也不能直接打印! # se.discard(11) # print(se) #移除指定元素,移除不存在的时候,不会报错 # se.remove(11) # print(se) #移除指定的元素,移除不存在的会报错 # se.pop() # print(se) #移除随机的元素 # # # ret=se.pop() # print(ret) #移除元素,并且可以把移除的元素赋值给另一个变量 # ce = se.intersection(be) # print(ce) #取出两个集合的交集(相同的元素) # se.intersection_update(be) # print(se) #取出两个集合的交集,并更新到se集合中 # ret = se.isdisjoint(be) # print(ret) #判断两个集合之间又没有交集,如果有交集返回False,没有返回True # ret=se.issubset(be) # print(ret) #判断se是否是be集合的子序列,如果是返回True,不是返回Flase # ret = se.issuperset(be) # print(ret) #判断se是不是be集合的父序列,如果是返回True,不是返回Flase # ret=se.symmetric_difference(be) # print(ret) #对称交集,取出除了不相同的元素 # se.symmetric_difference_update(be) # print(se) #对称交集,取出不相同的元素并更新到se集合中 # ret = se.union(be) # print(ret) #并集,把两个元素集合并在一个新的变量中
    2、深浅拷贝
    a、数字和字符串
    对于 数字 和 字符串 而言,赋值、浅拷贝和深拷贝无意义,因为其永远指向同一个内存地址。
    import copy # ######### 数字、字符串 ######### n1 = 123 # n1 = "i am alex age 10" print(id(n1)) # ## 赋值 ## n2 = n1 print(id(n2)) # ## 浅拷贝 ## n2 = copy.copy(n1) print(id(n2)) # ## 深拷贝 ## n3 = copy.deepcopy(n1) print(id(n3))
    b、其他基本数据类型
    对于字典、元祖、列表 而言,进行赋值、浅拷贝和深拷贝时,其内存地址的变化是不同的。
    1、赋值
    赋值,只是创建一个变量,该变量指向原来内存地址,如:
    n1 = {"k1": "zhangyanlin", "k2": 123, "k3": ["Aylin", 456]} n2 = n1
    2、浅拷贝
    浅拷贝,在内存中只额外创建第一层数据
    import copy n1 = {"k1": "zhangyanlin", "k2": 123, "k3": ["aylin", 456]} n3 = copy.copy(n1)
    3、深拷贝
    深拷贝,在内存中将所有的数据重新创建一份(排除最后一层,即:python内部对字符串和数字的优化)
    1、返回值
    函数是一个功能块,该功能到底执行成功与否,需要通过返回值来告知调用者。
    以上要点中,比较重要有参数和返回值:
    def 发送短信(): 发送短信的代码... if 发送成功: return True else: return False while True: # 每次执行发送短信函数,都会将返回值自动赋值给result # 之后,可以根据result来写日志,或重发等操作 result = 发送短信() if result == False: 短信发送失败...
    函数的有三中不同的参数:
    普通参数
    # ######### 定义函数 #########

    # name 叫做函数func的形式参数,简称:形参
    def func(name):
    print name

    # ######### 执行函数 #########
    # 'zhangyanlin' 叫做函数func的实际参数,简称:实参
    func('zhangyanlin')
    默认参数
    def func(name, age = 18):

    print "%s:%s" %(name,age)

    # 指定参数
    func('zhangyanlin', 19)
    # 使用默认参数
    func('nick')
    注:默认参数需要放在参数列表最后
      
    动态参数
    def func(*args): print args # 执行方式一 func(11,33,4,4454,5) # 执行方式二 li = [11,2,2,3,3,4,54] func(*li)   
    def func(**kwargs): print args # 执行方式一 func(name='wupeiqi',age=18) # 执行方式二 li = {'name':'wupeiqi', age:18, 'gender':'male'} func(**li)
     def func(*args, **kwargs): print args print kwargs
    邮件实例:
    def email(p,j,k): import smtplib from email.mime.text import MIMEText from email.utils import formataddr set = True try: msg = MIMEText('j', 'plain', 'utf-8') #j 邮件内容 msg['From'] = formataddr(["武沛齐",'wptawy@126.com']) msg['To'] = formataddr(["走人",'424662508@qq.com']) msg['Subject'] = "k" #k主题 server = smtplib.SMTP("smtp.126.com", 25) server.login("wptawy@126.com", "WW.3945.59") server.sendmail('wptawy@126.com', [p], msg.as_string()) server.quit() except: set = False return True formmail = input("请你输入收件人邮箱:") zhuti = input("请您输入邮件主题:") neirOng= input("请您输入邮件内容:") aa=email(formmail,neirong,zhuti) if aa: print("邮件发送成功!") else: print("邮件发送失败!")


    更多 Python常用知识点相关文章请关注PHP中文网!
    回复

    使用道具 举报

    您需要登录后才可以回帖 登录 | 立即注册

    本版积分规则

    在我站开通SVIP可同时获得17个站点VIP资源 立即登录 立即注册
    快速回复 返回顶部 返回列表