python之列表、字典、集合


列表

name = ["Alex","Eenglan","Eric"]
print(name[0])
print(name[1])
print(name[2])

運行如下

 

下標

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
print(name[1:4])   #取下標1到下標4之間的數字,包括1,不包括4.顧頭不顧尾。
print(name[1:-1])  #取下標1到-1的值,不包括-1
print(name[::2])  #取下標0到之后所有,每隔兩個取一個
print(name[-1])  #取下標最后一個

 


追加 
append

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
name.append("Lilei")  #追加Lilei到最后一個
print(name)

運行如下

 

 

插入  insert

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
name.insert(2,"Lilei")  #Lilei插入到下標為2的位置
print(name)

運行如下

 

修改

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
name[2]="Lilei"   #修改下標是2的字符串為Lilei
print(name)

運行如下

 

 

刪除三種方法

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
name.remove("Tom")  # 刪除字符串Tom
print(name)

name1 = ["Alex","Eenglan","Eric","Rain","World","Tom"]
del name1[-1]         #刪除下標為-1列表
print(name1)

name2 = ["Alex","Eenglan","Eric","Rain","World","Tom"]
name2.pop()         #刪除最后一個
print(name2)

運行如下

 

 


擴展  extend

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
b = ["1","2","3"]
name.extend(b)    #列表中使用列表
print(name)

運行如下

 

拷貝  copy

name = ["Alex","Eenglan","Eric","Rain","World","Tom"]
b = name.copy()    #拷貝name的內容
print(b)

運行如下

 

統計  count

name = ["Alex","Alex","Eric","Alex","World","Tom"]
print(name.count("Alex"))   #統計Alex有幾個

運行如下

排序&反轉  sort & reverse

name = ["Alex","Lilei","Eric","1","2","3"]
name.sort()  #排序,ask碼排序
print(name)
name.reverse()   #反轉排序
print(name)

運行如下

 

獲取下標  index

name = ["Alex","Lilei","Eric","1","2","3"]
print(name.index("Lilei"))   #獲取Lilei的下標

運行如下

 

 

元組

元組和列表差不多,就是存放一組數據,只不過一旦創建不能修改,而列表可以修改

name = ("Alex","Lilei","Eric","Lilei","2","3")
print(name.index("Lilei"))   #獲取Lilei的下標,但是只能找到第一個
print(name.count("Lilei"))   #獲取Lilei的重復次數

運行如下

 

 

 

字符串操作

移出空白

msg='        asdada\n'
print(msg.strip())

運行如下

分割取值

msg='my name is lilei'
print(msg[4:6])
print(msg[4])
print(msg[4:6:2]) #4-6范圍內每隔2個取一個

運行如下

 

長度

lilei='12345'
print(len(lilei))        #查看變量的長度

運行如下

字符串工廠函數

class str(object):
    """
    str(object='') -> str
    str(bytes_or_buffer[, encoding[, errors]]) -> str

    Create a new string object from the given object. If encoding or
    errors is specified, then the object must expose a data buffer
    that will be decoded using the given encoding and error handler.
    Otherwise, returns the result of object.__str__() (if defined)
    or repr(object).
    encoding defaults to sys.getdefaultencoding().
    errors defaults to 'strict'.
    """
    def capitalize(self): # real signature unknown; restored from __doc__
        """
        首字母變大寫
        S.capitalize() -> str

        Return a capitalized version of S, i.e. make the first character
        have upper case and the rest lower case.
        """
        return ""

    def casefold(self): # real signature unknown; restored from __doc__
        """
        S.casefold() -> str

        Return a version of S suitable for caseless comparisons.
        """
        return ""

    def center(self, width, fillchar=None): # real signature unknown; restored from __doc__
        """
        原來字符居中,不夠用空格補全
        S.center(width[, fillchar]) -> str

        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): # real signature unknown; restored from __doc__
        """
         從一個范圍內的統計某str出現次數
        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 encode(self, encoding='utf-8', errors='strict'): # real signature unknown; restored from __doc__
        """
        encode(encoding='utf-8',errors='strict')
        以encoding指定編碼格式編碼,如果出錯默認報一個ValueError,除非errors指定的是
        ignore或replace

        S.encode(encoding='utf-8', errors='strict') -> bytes

        Encode S using the codec registered for encoding. Default encoding
        is 'utf-8'. 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 can handle UnicodeEncodeErrors.
        """
        return b""

    def endswith(self, suffix, start=None, end=None): # real signature unknown; restored from __doc__
        """
        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=8): # real signature unknown; restored from __doc__
        """
        將字符串中包含的\t轉換成tabsize個空格
        S.expandtabs(tabsize=8) -> str

        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): # real signature unknown; restored from __doc__
        """
        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(self, *args, **kwargs): # known special case of str.format
        """
        格式化輸出
        三種形式:
        形式一.
        >>> print('{0}{1}{0}'.format('a','b'))
        aba

        形式二:(必須一一對應)
        >>> print('{}{}{}'.format('a','b'))
        Traceback (most recent call last):
          File "<input>", line 1, in <module>
        IndexError: tuple index out of range
        >>> print('{}{}'.format('a','b'))
        ab

        形式三:
        >>> print('{name} {age}'.format(age=12,name='lhf'))
        lhf 12

        S.format(*args, **kwargs) -> str

        Return a formatted version of S, using substitutions from args and kwargs.
        The substitutions are identified by braces ('{' and '}').
        """
        pass

    def format_map(self, mapping): # real signature unknown; restored from __doc__
        """
        與format區別
        '{name}'.format(**dict(name='alex'))
        '{name}'.format_map(dict(name='alex'))

        S.format_map(mapping) -> str

        Return a formatted version of S, using substitutions from mapping.
        The substitutions are identified by braces ('{' and '}').
        """
        return ""

    def index(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """
        S.index(sub[, start[, end]]) -> int

        Like S.find() but raise ValueError when the substring is not found.
        """
        return 0

    def isalnum(self): # real signature unknown; restored from __doc__
        """
        至少一個字符,且都是字母或數字才返回True

        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): # real signature unknown; restored from __doc__
        """
        至少一個字符,且都是字母才返回True
        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 isdecimal(self): # real signature unknown; restored from __doc__
        """
        S.isdecimal() -> bool

        Return True if there are only decimal characters in S,
        False otherwise.
        """
        return False

    def isdigit(self): # real signature unknown; restored from __doc__
        """
        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 isidentifier(self): # real signature unknown; restored from __doc__
        """
        字符串為關鍵字返回True

        S.isidentifier() -> bool

        Return True if S is a valid identifier according
        to the language definition.

        Use keyword.iskeyword() to test for reserved identifiers
        such as "def" and "class".
        """
        return False

    def islower(self): # real signature unknown; restored from __doc__
        """
        至少一個字符,且都是小寫字母才返回True
        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 isnumeric(self): # real signature unknown; restored from __doc__
        """
        S.isnumeric() -> bool

        Return True if there are only numeric characters in S,
        False otherwise.
        """
        return False

    def isprintable(self): # real signature unknown; restored from __doc__
        """
        S.isprintable() -> bool

        Return True if all characters in S are considered
        printable in repr() or S is empty, False otherwise.
        """
        return False

    def isspace(self): # real signature unknown; restored from __doc__
        """
        至少一個字符,且都是空格才返回True
        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): # real signature unknown; restored from __doc__
        """
        >>> a='Hello'
        >>> a.istitle()
        True
        >>> a='HellP'
        >>> a.istitle()
        False

        S.istitle() -> bool

        Return True if S is a titlecased string and there is at least one
        character in S, i.e. upper- and titlecase characters may only
        follow uncased characters and lowercase characters only cased ones.
        Return False otherwise.
        """
        return False

    def isupper(self): # real signature unknown; restored from __doc__
        """
        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): # real signature unknown; restored from __doc__
        """
        #對序列進行操作(分別使用' '與':'作為分隔符)
        >>> seq1 = ['hello','good','boy','doiido']
        >>> print ' '.join(seq1)
        hello good boy doiido
        >>> print ':'.join(seq1)
        hello:good:boy:doiido


        #對字符串進行操作

        >>> seq2 = "hello good boy doiido"
        >>> print ':'.join(seq2)
        h:e:l:l:o: :g:o:o:d: :b:o:y: :d:o:i:i:d:o


        #對元組進行操作

        >>> seq3 = ('hello','good','boy','doiido')
        >>> print ':'.join(seq3)
        hello:good:boy:doiido


        #對字典進行操作

        >>> seq4 = {'hello':1,'good':2,'boy':3,'doiido':4}
        >>> print ':'.join(seq4)
        boy:good:doiido:hello


        #合並目錄

        >>> import os
        >>> os.path.join('/hello/','good/boy/','doiido')
        '/hello/good/boy/doiido'


        S.join(iterable) -> str

        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): # real signature unknown; restored from __doc__
        """
        S.ljust(width[, fillchar]) -> str

        Return S left-justified in a Unicode string of length width. Padding is
        done using the specified fill character (default is a space).
        """
        return ""

    def lower(self): # real signature unknown; restored from __doc__
        """
        S.lower() -> str

        Return a copy of the string S converted to lowercase.
        """
        return ""

    def lstrip(self, chars=None): # real signature unknown; restored from __doc__
        """
        S.lstrip([chars]) -> str

        Return a copy of the string S with leading whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        """
        return ""

    def maketrans(self, *args, **kwargs): # real signature unknown
        """
        Return a translation table usable for str.translate().

        If there is only one argument, it must be a dictionary mapping Unicode
        ordinals (integers) or characters to Unicode ordinals, strings or None.
        Character keys will be then converted to ordinals.
        If there are two arguments, they must be strings of equal length, and
        in the resulting dictionary, each character in x will be mapped to the
        character at the same position in y. If there is a third argument, it
        must be a string, whose characters will be mapped to None in the result.
        """
        pass

    def partition(self, sep): # real signature unknown; restored from __doc__
        """
        以sep為分割,將S分成head,sep,tail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): # real signature unknown; restored from __doc__
        """
        S.replace(old, new[, count]) -> str

        Return a copy of 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): # real signature unknown; restored from __doc__
        """
        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): # real signature unknown; restored from __doc__
        """
        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): # real signature unknown; restored from __doc__
        """
        S.rjust(width[, fillchar]) -> str

        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): # real signature unknown; restored from __doc__
        """
        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=-1): # real signature unknown; restored from __doc__
        """
        S.rsplit(sep=None, maxsplit=-1) -> list of strings

        Return a list of the words in 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, any whitespace string
        is a separator.
        """
        return []

    def rstrip(self, chars=None): # real signature unknown; restored from __doc__
        """
        S.rstrip([chars]) -> str

        Return a copy of the string S with trailing whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        """
        return ""

    def split(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__
        """
        以sep為分割,將S切分成列表,與partition的區別在於切分結果不包含sep,
        如果一個字符串中包含多個sep那么maxsplit為最多切分成幾部分
        >>> a='a,b c\nd\te'
        >>> a.split()
        ['a,b', 'c', 'd', 'e']
        S.split(sep=None, maxsplit=-1) -> list of strings

        Return a list of the words in 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=None): # real signature unknown; restored from __doc__
        """
        Python splitlines() 按照行('\r', '\r\n', \n')分隔,
        返回一個包含各行作為元素的列表,如果參數 keepends 為 False,不包含換行符,如        果為 True,則保留換行符。
        >>> x
        'adsfasdf\nsadf\nasdf\nadf'
        >>> x.splitlines()
        ['adsfasdf', 'sadf', 'asdf', 'adf']
        >>> x.splitlines(True)
        ['adsfasdf\n', 'sadf\n', 'asdf\n', 'adf']

        S.splitlines([keepends]) -> 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): # real signature unknown; restored from __doc__
        """
        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): # real signature unknown; restored from __doc__
        """
        S.strip([chars]) -> str

        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.
        """
        return ""

    def swapcase(self): # real signature unknown; restored from __doc__
        """
        大小寫反轉
        S.swapcase() -> str

        Return a copy of S with uppercase characters converted to lowercase
        and vice versa.
        """
        return ""

    def title(self): # real signature unknown; restored from __doc__
        """
        S.title() -> str

        Return a titlecased version of S, i.e. words start with title case
        characters, all remaining cased characters have lower case.
        """
        return ""

    def translate(self, table): # real signature unknown; restored from __doc__
        """
        table=str.maketrans('alex','big SB')

        a='hello abc'
        print(a.translate(table))

        S.translate(table) -> str

        Return a copy of the string S in which each character has been mapped
        through the given translation table. The table must implement
        lookup/indexing via __getitem__, for instance a dictionary or list,
        mapping Unicode ordinals to Unicode ordinals, strings, or None. If
        this operation raises LookupError, the character is left untouched.
        Characters mapped to None are deleted.
        """
        return ""

    def upper(self): # real signature unknown; restored from __doc__
        """
        S.upper() -> str

        Return a copy of S converted to uppercase.
        """
        return ""

    def zfill(self, width): # real signature unknown; restored from __doc__
        """
        原來字符右對齊,不夠用0補齊
        
        S.zfill(width) -> str

        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 __add__(self, *args, **kwargs): # real signature unknown
        """ Return self+value. """
        pass

    def __contains__(self, *args, **kwargs): # real signature unknown
        """ Return key in self. """
        pass

    def __eq__(self, *args, **kwargs): # real signature unknown
        """ Return self==value. """
        pass

    def __format__(self, format_spec): # real signature unknown; restored from __doc__
        """
        S.__format__(format_spec) -> str

        Return a formatted version of S as described by format_spec.
        """
        return ""

    def __getattribute__(self, *args, **kwargs): # real signature unknown
        """ Return getattr(self, name). """
        pass

    def __getitem__(self, *args, **kwargs): # real signature unknown
        """ Return self[key]. """
        pass

    def __getnewargs__(self, *args, **kwargs): # real signature unknown
        pass

    def __ge__(self, *args, **kwargs): # real signature unknown
        """ Return self>=value. """
        pass

    def __gt__(self, *args, **kwargs): # real signature unknown
        """ Return self>value. """
        pass

    def __hash__(self, *args, **kwargs): # real signature unknown
        """ Return hash(self). """
        pass

    def __init__(self, value='', encoding=None, errors='strict'): # known special case of str.__init__
        """
        str(object='') -> str
        str(bytes_or_buffer[, encoding[, errors]]) -> str

        Create a new string object from the given object. If encoding or
        errors is specified, then the object must expose a data buffer
        that will be decoded using the given encoding and error handler.
        Otherwise, returns the result of object.__str__() (if defined)
        or repr(object).
        encoding defaults to sys.getdefaultencoding().
        errors defaults to 'strict'.
        # (copied from class doc)
        """
        pass

    def __iter__(self, *args, **kwargs): # real signature unknown
        """ Implement iter(self). """
        pass

    def __len__(self, *args, **kwargs): # real signature unknown
        """ Return len(self). """
        pass

    def __le__(self, *args, **kwargs): # real signature unknown
        """ Return self<=value. """
        pass

    def __lt__(self, *args, **kwargs): # real signature unknown
        """ Return self<value. """
        pass

    def __mod__(self, *args, **kwargs): # real signature unknown
        """ Return self%value. """
        pass

    def __mul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value.n """
        pass

    @staticmethod # known case of __new__
    def __new__(*args, **kwargs): # real signature unknown
        """ Create and return a new object.  See help(type) for accurate signature. """
        pass

    def __ne__(self, *args, **kwargs): # real signature unknown
        """ Return self!=value. """
        pass

    def __repr__(self, *args, **kwargs): # real signature unknown
        """ Return repr(self). """
        pass

    def __rmod__(self, *args, **kwargs): # real signature unknown
        """ Return value%self. """
        pass

    def __rmul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value. """
        pass

    def __sizeof__(self): # real signature unknown; restored from __doc__
        """ S.__sizeof__() -> size of S in memory, in bytes """
        pass

    def __str__(self, *args, **kwargs): # real signature unknown
        """ Return str(self). """
        pass
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常用的,控制變量的類型

 


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