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Day02——Python基本数据类型
阅读量:6696 次
发布时间:2019-06-25

本文共 38831 字,大约阅读时间需要 129 分钟。

一、运算符

1.算数运算符

2.比较运算符

3.复制运算符

4.逻辑运算符

5.成员运算符

 二、基本数据类型

1.数字

整数(int)

在32位机器上,整数的位数为32位,取值范围为-2**31~2**31-1,即-2147483648~2147483647在64位系统上,整数的位数为64位,取值范围为-2**63~2**63-1,即-9223372036854775808~9223372036854775807

浮点数(fload)

浮点数也就是小数,之所以称为浮点数,是因为按照科学记数法表示时,一个浮点数的小数点位置是可变的,比如,1.23x109和12.3x108是完全相等的。 浮点数可以用数学写法,如1.23,3.14,-9.01,等等。但是对于很大或很小的浮点数,就必须用科学计数法表示,把10用e替代,1.23x109就是1.23e9,或者12.3e8,0.000012可以写成1.2e-5

2.布尔值

真或假1 或 0

3.字符串

str="Hello world ! "
字符串常用功能:
  • 移除空白  
    str.strip(self, chars=None)
    """ 移除两段空白 """
  • 分割  
    str.split(self, sep=None, maxsplit=None)
    """ 分割, maxsplit最多分割几次 """
  • 长度   ##len(str)
  • 索引   ##str[0]  获取字符串第一个元素
  • 切片                 
    [:] 提取从开头(默认位置0)到结尾(默认位置-1)的整个字符串
    str[::5]   [start:end:step]
    [:end] 从开头提取到end - 1 [start:end] 从start 提取到end - 1 [start:end:step] 从start 提取到end - 1,每step 个字符提取一个 左侧第一个字符的位置/偏移量为0,右侧最后一个字符的位置/偏移量为-1
  • 大小写转换
    str.swapcase(self)  """ 大写变小写,小写变大写 """
    str.upper(self)
    str.lower(self)
  • 替换
    str.replace(self, old, new, count=None)
  • 统计
    str.count('le')  ##统计le在str出现的次数
  • 格式输出

    str.center(50,"-")  

   ##输出 '--------------------- Hello world ! ----------------------'
class str(basestring):    """    str(object='') -> string        Return a nice string representation of the object.    If the argument is a string, the return value is the same object.    """    def capitalize(self):          """ 首字母变大写 """        """        S.capitalize() -> string                Return a copy of the string S with only its first character        capitalized.        """        return ""    def center(self, width, fillchar=None):          """ 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """        """        S.center(width[, fillchar]) -> string                Return S centered in a string of length width. Padding is        done using the specified fill character (default is a space)        """        return ""    def count(self, sub, start=None, end=None):          """ 子序列个数 """        """        S.count(sub[, start[, end]]) -> int                Return the number of non-overlapping occurrences of substring sub in        string S[start:end].  Optional arguments start and end are interpreted        as in slice notation.        """        return 0    def decode(self, encoding=None, errors=None):          """ 解码 """        """        S.decode([encoding[,errors]]) -> object                Decodes S using the codec registered for encoding. encoding defaults        to the default encoding. errors may be given to set a different error        handling scheme. Default is 'strict' meaning that encoding errors raise        a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'        as well as any other name registered with codecs.register_error that is        able to handle UnicodeDecodeErrors.        """        return object()    def encode(self, encoding=None, errors=None):          """ 编码,针对unicode """        """        S.encode([encoding[,errors]]) -> object                Encodes S using the codec registered for encoding. encoding defaults        to the default encoding. errors may be given to set a different error        handling scheme. Default is 'strict' meaning that encoding errors raise        a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and        'xmlcharrefreplace' as well as any other name registered with        codecs.register_error that is able to handle UnicodeEncodeErrors.        """        return object()    def endswith(self, suffix, start=None, end=None):          """ 是否以 xxx 结束 """        """        S.endswith(suffix[, start[, end]]) -> bool                Return True if S ends with the specified suffix, False otherwise.        With optional start, test S beginning at that position.        With optional end, stop comparing S at that position.        suffix can also be a tuple of strings to try.        """        return False    def expandtabs(self, tabsize=None):          """ 将tab转换成空格,默认一个tab转换成8个空格 """        """        S.expandtabs([tabsize]) -> string                Return a copy of S where all tab characters are expanded using spaces.        If tabsize is not given, a tab size of 8 characters is assumed.        """        return ""    def find(self, sub, start=None, end=None):          """ 寻找子序列位置,如果没找到,返回 -1 """        """        S.find(sub [,start [,end]]) -> int                Return the lowest index in S where substring sub is found,        such that sub is contained within S[start:end].  Optional        arguments start and end are interpreted as in slice notation.                Return -1 on failure.        """        return 0    def format(*args, **kwargs): # known special case of str.format        """ 字符串格式化,动态参数,将函数式编程时细说 """        """        S.format(*args, **kwargs) -> string                Return a formatted version of S, using substitutions from args and kwargs.        The substitutions are identified by braces ('{' and '}').        """        pass    def index(self, sub, start=None, end=None):          """ 子序列位置,如果没找到,报错 """        S.index(sub [,start [,end]]) -> int                Like S.find() but raise ValueError when the substring is not found.        """        return 0    def isalnum(self):          """ 是否是字母和数字 """        """        S.isalnum() -> bool                Return True if all characters in S are alphanumeric        and there is at least one character in S, False otherwise.        """        return False    def isalpha(self):          """ 是否是字母 """        """        S.isalpha() -> bool                Return True if all characters in S are alphabetic        and there is at least one character in S, False otherwise.        """        return False    def isdigit(self):          """ 是否是数字 """        """        S.isdigit() -> bool                Return True if all characters in S are digits        and there is at least one character in S, False otherwise.        """        return False    def islower(self):          """ 是否小写 """        """        S.islower() -> bool                Return True if all cased characters in S are lowercase and there is        at least one cased character in S, False otherwise.        """        return False    def isspace(self):          """        S.isspace() -> bool                Return True if all characters in S are whitespace        and there is at least one character in S, False otherwise.        """        return False    def istitle(self):          """        S.istitle() -> bool                Return True if S is a titlecased string and there is at least one        character in S, i.e. uppercase characters may only follow uncased        characters and lowercase characters only cased ones. Return False        otherwise.        """        return False    def isupper(self):          """        S.isupper() -> bool                Return True if all cased characters in S are uppercase and there is        at least one cased character in S, False otherwise.        """        return False    def join(self, iterable):          """ 连接 """        """        S.join(iterable) -> string                Return a string which is the concatenation of the strings in the        iterable.  The separator between elements is S.        """        return ""    def ljust(self, width, fillchar=None):          """ 内容左对齐,右侧填充 """        """        S.ljust(width[, fillchar]) -> string                Return S left-justified in a string of length width. Padding is        done using the specified fill character (default is a space).        """        return ""    def lower(self):          """ 变小写 """        """        S.lower() -> string                Return a copy of the string S converted to lowercase.        """        return ""    def lstrip(self, chars=None):          """ 移除左侧空白 """        """        S.lstrip([chars]) -> string or unicode                Return a copy of the string S with leading whitespace removed.        If chars is given and not None, remove characters in chars instead.        If chars is unicode, S will be converted to unicode before stripping        """        return ""    def partition(self, sep):          """ 分割,前,中,后三部分 """        """        S.partition(sep) -> (head, sep, tail)                Search for the separator sep in S, and return the part before it,        the separator itself, and the part after it.  If the separator is not        found, return S and two empty strings.        """        pass    def replace(self, old, new, count=None):          """ 替换 """        """        S.replace(old, new[, count]) -> string                Return a copy of string S with all occurrences of substring        old replaced by new.  If the optional argument count is        given, only the first count occurrences are replaced.        """        return ""    def rfind(self, sub, start=None, end=None):          """        S.rfind(sub [,start [,end]]) -> int                Return the highest index in S where substring sub is found,        such that sub is contained within S[start:end].  Optional        arguments start and end are interpreted as in slice notation.                Return -1 on failure.        """        return 0    def rindex(self, sub, start=None, end=None):          """        S.rindex(sub [,start [,end]]) -> int                Like S.rfind() but raise ValueError when the substring is not found.        """        return 0    def rjust(self, width, fillchar=None):          """        S.rjust(width[, fillchar]) -> string                Return S right-justified in a string of length width. Padding is        done using the specified fill character (default is a space)        """        return ""    def rpartition(self, sep):          """        S.rpartition(sep) -> (head, sep, tail)                Search for the separator sep in S, starting at the end of S, and return        the part before it, the separator itself, and the part after it.  If the        separator is not found, return two empty strings and S.        """        pass    def rsplit(self, sep=None, maxsplit=None):          """        S.rsplit([sep [,maxsplit]]) -> list of strings                Return a list of the words in the string S, using sep as the        delimiter string, starting at the end of the string and working        to the front.  If maxsplit is given, at most maxsplit splits are        done. If sep is not specified or is None, any whitespace string        is a separator.        """        return []    def rstrip(self, chars=None):          """        S.rstrip([chars]) -> string or unicode                Return a copy of the string S with trailing whitespace removed.        If chars is given and not None, remove characters in chars instead.        If chars is unicode, S will be converted to unicode before stripping        """        return ""    def split(self, sep=None, maxsplit=None):          """ 分割, maxsplit最多分割几次 """        """        S.split([sep [,maxsplit]]) -> list of strings                Return a list of the words in the string S, using sep as the        delimiter string.  If maxsplit is given, at most maxsplit        splits are done. If sep is not specified or is None, any        whitespace string is a separator and empty strings are removed        from the result.        """        return []    def splitlines(self, keepends=False):          """ 根据换行分割 """        """        S.splitlines(keepends=False) -> list of strings                Return a list of the lines in S, breaking at line boundaries.        Line breaks are not included in the resulting list unless keepends        is given and true.        """        return []    def startswith(self, prefix, start=None, end=None):          """ 是否起始 """        """        S.startswith(prefix[, start[, end]]) -> bool                Return True if S starts with the specified prefix, False otherwise.        With optional start, test S beginning at that position.        With optional end, stop comparing S at that position.        prefix can also be a tuple of strings to try.        """        return False    def strip(self, chars=None):          """ 移除两段空白 """        """        S.strip([chars]) -> string or unicode                Return a copy of the string S with leading and trailing        whitespace removed.        If chars is given and not None, remove characters in chars instead.        If chars is unicode, S will be converted to unicode before stripping        """        return ""    def swapcase(self):          """ 大写变小写,小写变大写 """        """        S.swapcase() -> string                Return a copy of the string S with uppercase characters        converted to lowercase and vice versa.        """        return ""    def title(self):          """        S.title() -> string                Return a titlecased version of S, i.e. words start with uppercase        characters, all remaining cased characters have lowercase.        """        return ""    def translate(self, table, deletechars=None):          """        转换,需要先做一个对应表,最后一个表示删除字符集合        intab = "aeiou"        outtab = "12345"        trantab = maketrans(intab, outtab)        str = "this is string example....wow!!!"        print str.translate(trantab, 'xm')        """        """        S.translate(table [,deletechars]) -> string                Return a copy of the string S, where all characters occurring        in the optional argument deletechars are removed, and the        remaining characters have been mapped through the given        translation table, which must be a string of length 256 or None.        If the table argument is None, no translation is applied and        the operation simply removes the characters in deletechars.        """        return ""    def upper(self):          """        S.upper() -> string                Return a copy of the string S converted to uppercase.        """        return ""    def zfill(self, width):          """方法返回指定长度的字符串,原字符串右对齐,前面填充0。"""        """        S.zfill(width) -> string                Pad a numeric string S with zeros on the left, to fill a field        of the specified width.  The string S is never truncated.        """        return ""    def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown        pass    def _formatter_parser(self, *args, **kwargs): # real signature unknown        pass    def __add__(self, y):          """ x.__add__(y) <==> x+y """        pass    def __contains__(self, y):          """ x.__contains__(y) <==> y in x """        pass    def __eq__(self, y):          """ x.__eq__(y) <==> x==y """        pass    def __format__(self, format_spec):          """        S.__format__(format_spec) -> string                Return a formatted version of S as described by format_spec.        """        return ""    def __getattribute__(self, name):          """ x.__getattribute__('name') <==> x.name """        pass    def __getitem__(self, y):          """ x.__getitem__(y) <==> x[y] """        pass    def __getnewargs__(self, *args, **kwargs): # real signature unknown        pass    def __getslice__(self, i, j):          """        x.__getslice__(i, j) <==> x[i:j]                                      Use of negative indices is not supported.        """        pass    def __ge__(self, y):          """ x.__ge__(y) <==> x>=y """        pass    def __gt__(self, y):          """ x.__gt__(y) <==> x>y """        pass    def __hash__(self):          """ x.__hash__() <==> hash(x) """        pass    def __init__(self, string=''): # known special case of str.__init__        """        str(object='') -> string                Return a nice string representation of the object.        If the argument is a string, the return value is the same object.        # (copied from class doc)        """        pass    def __len__(self):          """ x.__len__() <==> len(x) """        pass    def __le__(self, y):          """ x.__le__(y) <==> x<=y """        pass    def __lt__(self, y):          """ x.__lt__(y) <==> x
x%y """ pass def __mul__(self, n): """ x.__mul__(n) <==> x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): """ x.__repr__() <==> repr(x) """ pass def __rmod__(self, y): """ x.__rmod__(y) <==> y%x """ pass def __rmul__(self, n): """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): """ S.__sizeof__() -> size of S in memory, in bytes """ pass def __str__(self): """ x.__str__() <==> str(x) """ passstr
字符串类

4. 列表

列表创建

name_list = ['alex', 'seven', 'eric']或name_list = list(['alex', 'seven', 'eric'])

基本操作:

names = ['Alex',"Tenglan",'Eric']>>> names[0]'Alex'>>> names[2]'Eric'>>> names[-1]'Eric'>>> names[-2] #还可以倒着取'Tenglan'
索引
>>> names['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy']>>> names.append("我是新来的")>>> names['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']
追加
>>> names['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']>>> names.insert(2,"强行从Eric前面插入")>>> names['Alex', 'Tenglan', '强行从Eric前面插入', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']>>> names.insert(5,"从eric后面插入试试新姿势")>>> names['Alex', 'Tenglan', '强行从Eric前面插入', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的']
插入
>>> names['Alex', 'Tenglan', '强行从Eric前面插入', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的']>>> names[2] = "该换人了">>> names['Alex', 'Tenglan', '该换人了', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的']
修改
>>> del names[2] >>> names['Alex', 'Tenglan', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的']>>> del names[4]>>> names['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的']>>> >>> names.remove("Eric") #删除指定元素>>> names['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy', '我是新来的']>>> names.pop() #删除列表最后一个值 '我是新来的'>>> names['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy']
删除
>>> names['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy']>>> b = [1,2,3]>>> names.extend(b)>>> names['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy', 1, 2, 3]
扩展
>>> names = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]>>> names[1:4]  #取下标1至下标4之间的数字,包括1,不包括4['Tenglan', 'Eric', 'Rain']>>> names[1:-1] #取下标1至-1的值,不包括-1['Tenglan', 'Eric', 'Rain', 'Tom']>>> names[0:3] ['Alex', 'Tenglan', 'Eric']>>> names[:3] #如果是从头开始取,0可以忽略,跟上句效果一样['Alex', 'Tenglan', 'Eric']>>> names[3:] #如果想取最后一个,必须不能写-1,只能这么写['Rain', 'Tom', 'Amy'] >>> names[3:-1] #这样-1就不会被包含了['Rain', 'Tom']>>> names[0::2] #后面的2是代表,每隔一个元素,就取一个['Alex', 'Eric', 'Tom'] >>> names[::2] #和上句效果一样['Alex', 'Eric', 'Tom']
切片
class list(object):    """    list() -> new empty list    list(iterable) -> new list initialized from iterable's items    """    def append(self, p_object): # real signature unknown; restored from __doc__        """ L.append(object) -- append object to end """        pass    def count(self, value): # real signature unknown; restored from __doc__        """ L.count(value) -> integer -- return number of occurrences of value """        return 0    def extend(self, iterable): # real signature unknown; restored from __doc__        """ L.extend(iterable) -- extend list by appending elements from the iterable """        pass    def 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.        """        return 0    def insert(self, index, p_object): # real signature unknown; restored from __doc__        """ L.insert(index, object) -- insert object before index """        pass    def 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.        """        pass    def remove(self, value): # real signature unknown; restored from __doc__        """        L.remove(value) -- remove first occurrence of value.        Raises ValueError if the value is not present.        """        pass    def reverse(self): # real signature unknown; restored from __doc__        """ L.reverse() -- reverse *IN PLACE* """        pass    def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__        """        L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;        cmp(x, y) -> -1, 0, 1        """        pass    def __add__(self, y): # real signature unknown; restored from __doc__        """ x.__add__(y) <==> x+y """        pass    def __contains__(self, y): # real signature unknown; restored from __doc__        """ x.__contains__(y) <==> y in x """        pass    def __delitem__(self, y): # real signature unknown; restored from __doc__        """ x.__delitem__(y) <==> del x[y] """        pass    def __delslice__(self, i, j): # real signature unknown; restored from __doc__        """        x.__delslice__(i, j) <==> del x[i:j]                                      Use of negative indices is not supported.        """        pass    def __eq__(self, y): # real signature unknown; restored from __doc__        """ x.__eq__(y) <==> x==y """        pass    def __getattribute__(self, name): # real signature unknown; restored from __doc__        """ x.__getattribute__('name') <==> x.name """        pass    def __getitem__(self, y): # real signature unknown; restored from __doc__        """ x.__getitem__(y) <==> x[y] """        pass    def __getslice__(self, i, j): # real signature unknown; restored from __doc__        """        x.__getslice__(i, j) <==> x[i:j]                                      Use of negative indices is not supported.        """        pass    def __ge__(self, y): # real signature unknown; restored from __doc__        """ x.__ge__(y) <==> x>=y """        pass    def __gt__(self, y): # real signature unknown; restored from __doc__        """ x.__gt__(y) <==> x>y """        pass    def __iadd__(self, y): # real signature unknown; restored from __doc__        """ x.__iadd__(y) <==> x+=y """        pass    def __imul__(self, y): # real signature unknown; restored from __doc__        """ x.__imul__(y) <==> x*=y """        pass    def __init__(self, seq=()): # known special case of list.__init__        """        list() -> new empty list        list(iterable) -> new list initialized from iterable's items        # (copied from class doc)        """        pass    def __iter__(self): # real signature unknown; restored from __doc__        """ x.__iter__() <==> iter(x) """        pass    def __len__(self): # real signature unknown; restored from __doc__        """ x.__len__() <==> len(x) """        pass    def __le__(self, y): # real signature unknown; restored from __doc__        """ x.__le__(y) <==> x<=y """        pass    def __lt__(self, y): # real signature unknown; restored from __doc__        """ x.__lt__(y) <==> x
x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): # real signature unknown; restored from __doc__ """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): # real signature unknown; restored from __doc__ """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ pass def __reversed__(self): # real signature unknown; restored from __doc__ """ L.__reversed__() -- return a reverse iterator over the list """ pass def __rmul__(self, n): # real signature unknown; restored from __doc__ """ x.__rmul__(n) <==> n*x """ pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__ """ x.__setitem__(i, y) <==> x[i]=y """ pass def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__ """ x.__setslice__(i, j, y) <==> x[i:j]=y Use of negative indices is not supported. """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ L.__sizeof__() -- size of L in memory, in bytes """ pass __hash__ = Nonelist
列表类

 

5.元组

元组其实跟列表差不多,也是存一组数,只不是它一旦创建,便不能再修改,所以又叫只读列表

创建元组

ages = (11, 22, 33, 44, 55)或ages = tuple((11, 22, 33, 44, 55))
基本操作:
  • 索引
  • 切片
  • lass tuple(object):    """    tuple() -> empty tuple    tuple(iterable) -> tuple initialized from iterable's items        If the argument is a tuple, the return value is the same object.    """    def count(self, value): # real signature unknown; restored from __doc__        """ T.count(value) -> integer -- return number of occurrences of value """        return 0    def 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.        """        return 0    def __add__(self, y): # real signature unknown; restored from __doc__        """ x.__add__(y) <==> x+y """        pass    def __contains__(self, y): # real signature unknown; restored from __doc__        """ x.__contains__(y) <==> y in x """        pass    def __eq__(self, y): # real signature unknown; restored from __doc__        """ x.__eq__(y) <==> x==y """        pass    def __getattribute__(self, name): # real signature unknown; restored from __doc__        """ x.__getattribute__('name') <==> x.name """        pass    def __getitem__(self, y): # real signature unknown; restored from __doc__        """ x.__getitem__(y) <==> x[y] """        pass    def __getnewargs__(self, *args, **kwargs): # real signature unknown        pass    def __getslice__(self, i, j): # real signature unknown; restored from __doc__        """        x.__getslice__(i, j) <==> x[i:j]                                      Use of negative indices is not supported.        """        pass    def __ge__(self, y): # real signature unknown; restored from __doc__        """ x.__ge__(y) <==> x>=y """        pass    def __gt__(self, y): # real signature unknown; restored from __doc__        """ x.__gt__(y) <==> x>y """        pass    def __hash__(self): # real signature unknown; restored from __doc__        """ x.__hash__() <==> hash(x) """        pass    def __init__(self, seq=()): # known special case of tuple.__init__        """        tuple() -> empty tuple        tuple(iterable) -> tuple initialized from iterable's items                If the argument is a tuple, the return value is the same object.        # (copied from class doc)        """        pass    def __iter__(self): # real signature unknown; restored from __doc__        """ x.__iter__() <==> iter(x) """        pass    def __len__(self): # real signature unknown; restored from __doc__        """ x.__len__() <==> len(x) """        pass    def __le__(self, y): # real signature unknown; restored from __doc__        """ x.__le__(y) <==> x<=y """        pass    def __lt__(self, y): # real signature unknown; restored from __doc__        """ x.__lt__(y) <==> x
    x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): # real signature unknown; restored from __doc__ """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): # real signature unknown; restored from __doc__ """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ pass def __rmul__(self, n): # real signature unknown; restored from __doc__ """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ T.__sizeof__() -- size of T in memory, in bytes """ passtuple
    元组类

     

6.字典(无序)

字典是一种Key-value数据类型,无序但key必须是唯一值

创建字典

person = {
"name": "mr.wu", 'age': 18}或person = dict({
"name": "mr.wu", 'age': 18})

常用操作:

>>> info["stu1104"] = "苍井空">>> info{
'stu1102': 'LongZe Luola', 'stu1104': '苍井空', 'stu1103': 'XiaoZe Maliya', 'stu1101': 'TengLan Wu'}
增加
>>> info['stu1101'] = "武藤兰">>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1101': '武藤兰'}
修改
>>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1101': '武藤兰'}>>> info.pop("stu1101") #标准删除姿势'武藤兰'>>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}>>> del info['stu1103'] #换个姿势删除>>> info{
'stu1102': 'LongZe Luola'}>>> >>> >>> >>> info = {
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}>>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'} #随机删除>>> info.popitem()('stu1102', 'LongZe Luola')>>> info{
'stu1103': 'XiaoZe Maliya'}
删除
>>> info = {
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}>>> >>> "stu1102" in info #标准用法True>>> info.get("stu1102") #获取'LongZe Luola'>>> info["stu1102"] #同上,但是看下面'LongZe Luola'>>> info["stu1105"] #如果一个key不存在,就报错,get不会,不存在只返回NoneTraceback (most recent call last): File "
", line 1, in
KeyError: 'stu1105'
查找
av_catalog = {    "欧美":{        "www.youporn.com": ["很多免费的,世界最大的","质量一般"],        "www.pornhub.com": ["很多免费的,也很大","质量比yourporn高点"],        "letmedothistoyou.com": ["多是自拍,高质量图片很多","资源不多,更新慢"],        "x-art.com":["质量很高,真的很高","全部收费,屌比请绕过"]    },    "日韩":{        "tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","听说是收费的"]    },    "大陆":{        "1024":["全部免费,真好,好人一生平安","服务器在国外,慢"]    }}av_catalog["大陆"]["1024"][1] += ",可以用爬虫爬下来"print(av_catalog["大陆"]["1024"])#ouput ['全部免费,真好,好人一生平安', '服务器在国外,慢,可以用爬虫爬下来']
字典嵌套
#values>>> info.values()dict_values(['LongZe Luola', 'XiaoZe Maliya'])#keys>>> info.keys()dict_keys(['stu1102', 'stu1103'])#setdefault>>> info.setdefault("stu1106","Alex")'Alex'>>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'}>>> info.setdefault("stu1102","龙泽萝拉")'LongZe Luola'>>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'}#update >>> info{
'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'}>>> b = {1:2,3:4, "stu1102":"龙泽萝拉"}>>> info.update(b)>>> info{
'stu1102': '龙泽萝拉', 1: 2, 3: 4, 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'}#itemsinfo.items()dict_items([('stu1102', '龙泽萝拉'), (1, 2), (3, 4), ('stu1103', 'XiaoZe Maliya'), ('stu1106', 'Alex')])#通过一个列表生成默认dict,有个没办法解释的坑,少用吧这个>>> dict.fromkeys([1,2,3],'testd'){
1: 'testd', 2: 'testd', 3: 'testd'}
key-value
#方法1for key in info:    print(key,info[key])#方法2for k,v in info.items(): #会先把dict转成list,数据里大时莫用    print(k,v)
循环
  • class dict(object):    """    dict() -> new empty dictionary    dict(mapping) -> new dictionary initialized from a mapping object's        (key, value) pairs    dict(iterable) -> new dictionary initialized as if via:        d = {}        for k, v in iterable:            d[k] = v    dict(**kwargs) -> new dictionary initialized with the name=value pairs        in the keyword argument list.  For example:  dict(one=1, two=2)    """    def clear(self): # real signature unknown; restored from __doc__        """ 清除内容 """        """ D.clear() -> None.  Remove all items from D. """        pass    def copy(self): # real signature unknown; restored from __doc__        """ 浅拷贝 """        """ D.copy() -> a shallow copy of D """        pass    @staticmethod # known case    def fromkeys(S, v=None): # real signature unknown; restored from __doc__        """        dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.        v defaults to None.        """        pass    def get(self, k, d=None): # real signature unknown; restored from __doc__        """ 根据key获取值,d是默认值 """        """ D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None. """        pass    def has_key(self, k): # real signature unknown; restored from __doc__        """ 是否有key """        """ D.has_key(k) -> True if D has a key k, else False """        return False    def items(self): # real signature unknown; restored from __doc__        """ 所有项的列表形式 """        """ D.items() -> list of D's (key, value) pairs, as 2-tuples """        return []    def iteritems(self): # real signature unknown; restored from __doc__        """ 项可迭代 """        """ D.iteritems() -> an iterator over the (key, value) items of D """        pass    def iterkeys(self): # real signature unknown; restored from __doc__        """ key可迭代 """        """ D.iterkeys() -> an iterator over the keys of D """        pass    def itervalues(self): # real signature unknown; restored from __doc__        """ value可迭代 """        """ D.itervalues() -> an iterator over the values of D """        pass    def keys(self): # real signature unknown; restored from __doc__        """ 所有的key列表 """        """ D.keys() -> list of D's keys """        return []    def pop(self, k, d=None): # real signature unknown; restored from __doc__        """ 获取并在字典中移除 """        """        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        """        pass    def popitem(self): # real signature unknown; restored from __doc__        """ 获取并在字典中移除 """        """        D.popitem() -> (k, v), remove and return some (key, value) pair as a        2-tuple; but raise KeyError if D is empty.        """        pass    def setdefault(self, k, d=None): # real signature unknown; restored from __doc__        """ 如果key不存在,则创建,如果存在,则返回已存在的值且不修改 """        """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """        pass    def update(self, E=None, **F): # known special case of dict.update        """ 更新            {'name':'alex', 'age': 18000}            [('name','sbsbsb'),]        """        """        D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.        If E present and has a .keys() method, does:     for k in E: D[k] = E[k]        If E present and lacks .keys() method, does:     for (k, v) in E: D[k] = v        In either case, this is followed by: for k in F: D[k] = F[k]        """        pass    def values(self): # real signature unknown; restored from __doc__        """ 所有的值 """        """ D.values() -> list of D's values """        return []    def viewitems(self): # real signature unknown; restored from __doc__        """ 所有项,只是将内容保存至view对象中 """        """ D.viewitems() -> a set-like object providing a view on D's items """        pass    def viewkeys(self): # real signature unknown; restored from __doc__        """ D.viewkeys() -> a set-like object providing a view on D's keys """        pass    def viewvalues(self): # real signature unknown; restored from __doc__        """ D.viewvalues() -> an object providing a view on D's values """        pass    def __cmp__(self, y): # real signature unknown; restored from __doc__        """ x.__cmp__(y) <==> cmp(x,y) """        pass    def __contains__(self, k): # real signature unknown; restored from __doc__        """ D.__contains__(k) -> True if D has a key k, else False """        return False    def __delitem__(self, y): # real signature unknown; restored from __doc__        """ x.__delitem__(y) <==> del x[y] """        pass    def __eq__(self, y): # real signature unknown; restored from __doc__        """ x.__eq__(y) <==> x==y """        pass    def __getattribute__(self, name): # real signature unknown; restored from __doc__        """ x.__getattribute__('name') <==> x.name """        pass    def __getitem__(self, y): # real signature unknown; restored from __doc__        """ x.__getitem__(y) <==> x[y] """        pass    def __ge__(self, y): # real signature unknown; restored from __doc__        """ x.__ge__(y) <==> x>=y """        pass    def __gt__(self, y): # real signature unknown; restored from __doc__        """ x.__gt__(y) <==> x>y """        pass    def __init__(self, seq=None, **kwargs): # known special case of dict.__init__        """        dict() -> new empty dictionary        dict(mapping) -> new dictionary initialized from a mapping object's            (key, value) pairs        dict(iterable) -> new dictionary initialized as if via:            d = {}            for k, v in iterable:                d[k] = v        dict(**kwargs) -> new dictionary initialized with the name=value pairs            in the keyword argument list.  For example:  dict(one=1, two=2)        # (copied from class doc)        """        pass    def __iter__(self): # real signature unknown; restored from __doc__        """ x.__iter__() <==> iter(x) """        pass    def __len__(self): # real signature unknown; restored from __doc__        """ x.__len__() <==> len(x) """        pass    def __le__(self, y): # real signature unknown; restored from __doc__        """ x.__le__(y) <==> x<=y """        pass    def __lt__(self, y): # real signature unknown; restored from __doc__        """ x.__lt__(y) <==> x
    a new object with type S, a subtype of T """ pass def __ne__(self, y): # real signature unknown; restored from __doc__ """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__ """ x.__setitem__(i, y) <==> x[i]=y """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ D.__sizeof__() -> size of D in memory, in bytes """ pass __hash__ = Nonedict
    字典类

     

 7.其他 

for循环(支持break ,continue)li = [11,22,33,44]for item in li:    print itemenumrate(为可迭代对象添加序号)li = [11,22,33]for k,v in enumerate(li, 1):    print(k,v)range和xrange(指定范围,生成随机数)print range(1, 10)# 结果:[1, 2, 3, 4, 5, 6, 7, 8, 9] print range(1, 10, 2)# 结果:[1, 3, 5, 7, 9] print range(30, 0, -2)# 结果:[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2] 

三、练习题 

1、元素分类 

有如下值集合 [11,22,33,44,55,66,77,88,99,90...],将所有大于 66 的值保存至字典的第一个key中,将小于 66 的值保存至第二个key的值中。

即: {'k1': 大于66的所有值, 'k2': 小于66的所有值}
2、查找
查找列表中元素,移除每个元素的空格,并查找以 a或A开头 并且以 c 结尾的所有元素。
li = ["alec", " aric", "Alex", "Tony", "rain"]
tu = ("alec", " aric", "Alex", "Tony", "rain")
dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"}
3、输出商品列表,用户输入序号,显示用户选中的商品
商品 li = ["手机", "电脑", '鼠标垫', '游艇']
4、购物车 

功能要求: 

要求用户输入总资产,例如:2000

显示商品列表,让用户根据序号选择商品,加入购物车
购买,如果商品总额大于总资产,提示账户余额不足,否则,购买成功。
附加:可充值、某商品移除购物车 

goods = [

{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 998},

5、用户交互,显示省市县三级联动的选择 

dic = {

"河北": {
"石家庄": ["鹿泉", "藁城", "元氏"],
"邯郸": ["永年", "涉县", "磁县"],
}
"河南": {
...
}
"山西": {
...
}

转载于:https://www.cnblogs.com/rangle/p/8310634.html

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