• 第三天学习总结


    #######################list 类 列表########################
    li = [1, 2, 343, 'dfas', ['fsad', 'dfas'], True]
    # list 是一个集合 能放任何东西进去
    # print(li[0:3])
    # list 是可以修改的
    
    # 索引法
    # li[1]
    # a = li[4][0] value = 'fsad'
    
    # 切片法
    # li[3:5] = [3223,3432]
    
    # 列表中的元素是以,分割 一个一个是整体
    # li[1] = 'fdasdf'
    # print(li)
    
    # in 操作
    
    # for 循环 while循环
    tuple
    # 删除
    # del li[1]
    list
    #####转换
    # 字符串转化为列表 li = list['dfsadfasdf']
    #若列表里只有字符串
    '''li = ['dfas','fdsaf']
        v = "".join(li)
        print(v)
    '''
    #列表里不只有字符串 可以使用for循环
    '''
    s = ""
    for itm in li:
        s = s + str(itm)
    print(itm)    
    '''
    # list类中提供的方法
    '''
        l、li.append(self, p_object):  # real signature unknown; restored from __doc__
        """ L.append(object) -> None -- append object to end """
         v = li.append(5) 原值最后追加 v的value 位none
         li.append(['',''])
        2、清空列表
         li.clear()
        3、拷贝
         count(self, value): # real signature unknown; restored from __doc__
         L.count(value) -> integer -- return number of occurrences of value 
        4、计数
         count(self, value): # real signature unknown; restored from __doc__
         L.count(value) -> integer -- return number of occurrences of value 
        5、扩展原列表 参数为可迭代对象:字符串、列表框、元组  注意和append的区别
         extend(self, iterable): # real signature unknown; restored from __doc__
         L.extend(iterable) -> None -- extend list by appending elements from the iterable 
         li = [112,232,3213,3]
         li.append([213,3213])
         print(li)
         [112,232,3213,3,[213,3213]]
         
             li = [112,232,3213,3]
             li.extend([213,3213])
             print(li)
             [112,232,3213,3,213,3213]
        6、根据索引值获取位置 index
          index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
          L.index(value, [start, [stop]]) -> integer -- return first index of value.
          Raises ValueError if the value is not present.
        7、在指定索引位置插值 insert
         insert(self, index, p_object): # real signature unknown; restored from __doc__
         L.insert(index, object) -- insert object before index 
        8、删除索引对应的值 不指定索引默认最后一个值 并获取删除值
         pop(self, index=None): # real signature unknown; restored from __doc__
         L.pop([index]) -> item -- remove and return item at index (default last).
         Raises IndexError if list is empty or index is out of range.
         li = [112,232,3213,3]
         v = li.[1]
         print(v,li)
         232
         [112,3213,3]    
         9、选择删除值 remove
          remove(self, value): # real signature unknown; restored from __doc__
            """
            L.remove(value) -> None -- remove first occurrence of value.
            Raises ValueError if the value is not present.
            """
    # pop remove del li[0]   del li[1:2]
        10、反转 reverse
         reverse(self): # real signature unknown; restored from __doc__
            """ L.reverse() -- reverse *IN PLACE* """
        11、排序 sort
         sort(self, key=None, reverse=False): # real signature unknown; restored from __doc__
            """ L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE* """
            reverse = False 从小到大排序
    #list 有序且可以被修改
        
    '''
    dict
    ###########################元组tuple#########################
    '''
    元组一旦被创建  一级元素不可修改、不能被增加和删除 嵌套的列表框可以修改
    tuple 是有序的
    可以进行索引
    可以进行切片
    可以进行for 循环 while循环
    最好创建的时候加一个小逗号 tup = (fasdf,fdsfdfd,)
    tu = (dfas,erw,rewr,[(33,44)],4234) #获取33
    v = tu[3][0][0]
    print(v)
    33
    
    b = tu[3][0] =234
    print(b)
    tu = (dfas,erw,rewr,[234],4234)
    #############list方法
        1、计数 count
         count(self, value): # real signature unknown; restored from __doc__
         """ T.count(value) -> integer -- return number of occurrences of value """
            return 0
        2、找寻 index
         index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
         """
         T.index(value, [start, [stop]]) -> integer -- return first index of value.
          Raises ValueError if the value is not present.
          """
    
    '''
    ############################字典 #############
    '''
    info = {"k1":v1,"k2":"v2"}  #"k1":"v1" 键值对  
    key:value   value 可以为任意值
    key : 数字、字符串、元组 都可以  列表不可以 哈希表
    #索引使用key值 自己申明的
    #无序状态无法切片
    #删除
        del info[key]
    # for 循环 默认只循环key
        for item in info.keys
        for item in info.values
        for item in info .items  键值对
    ####or  for item in info.keys
            print(item,info[item])
    True 1  False 0 作为key 可能与1 重复
    '''
    ####################dict 常用方法
    '''
        1、dict()
        2、clear(self): # real signature unknown; restored from __doc__
            """ D.clear() -> None.  Remove all items from D. """
            pass
    
        3、 copy(self): # real signature unknown; restored from __doc__
            """ D.copy() -> a shallow copy of D """
            pass
    
        4、@staticmethod # known case直接写个类名就可以了 静态方法
          fromkeys(*args, **kwargs): # real signature unknown 第一个参数为key 第二个参数为value
            """ Returns a new dict with keys from iterable and values equal to value. """ 创建字典,指定统一的值
            pass
    
    ####5、get(self, k, d=None): # real signature unknown; restored from __doc__
            """ D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None. """
          根据key取value值 key不存在时返回d值 d默认值为none
        6、pop(self, k, d=None): # real signature unknown; restored from __doc__
            """
            D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
            If key is not found, d is returned if given, otherwise KeyError is raised
            删除值 若key值不存在返回d
        7、popitem(self): # real signature unknown; restored from __doc__
            """
            D.popitem() -> (k, v), remove and return some (key, value) pair as a
            2-tuple; but raise KeyError if D is empty.
            """随机删除一对键值对
        8、setdefault(self, k, d=None): # real signature unknown; restored from __doc__
            """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
            设置值:如果已经存在的key 不设置 获取原对应的value
                    若不存在 设置该value
        9、update(self, E=None, **F): # known special case of dict.update
            """
            D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
            If E is present and has a .keys() method, then does:  for k in E: D[k] = E[k]
            If E is present and lacks a .keys() method, then does:  for k, v in E: D[k] = v
            In either case, this is followed by: for k in F:  D[k] = F[k]
            """
            已经存在 覆盖掉
            不存在 赋值
            dic.update(k1=123,k3=234,k5="dfas") 自动转换成字典 
        
    
    
    
    '''
    ###############################大整理#####################
    '''
    #数字
        int
    #字符串
        replace
        find 
        join
        strip
        startwith
        endwith
        upper
        lower
        format  特殊的 v = template.format(**{name:'fdsa',age:'fdasf'}) 
    #列表
        append 
        extend 
        insert
        索引、切片、循环
    #元组 忽略
    #字典
        get 
        update
        keys
        values
        items
        for 
        索引
    #布尔值
    0 1 
    bool()
    为假的:none ()  0  '' [] {}
    
    
    
    
    
    '''
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  • 原文地址:https://www.cnblogs.com/zy0718/p/8436927.html
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