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  • 4、python基本知识点及字符串常用方法

    查看变量内存地址   id(变量名)

    ni = 123

    n2 = 123

    ni和n2肯定是用的两份内存,但是python对于数字在-5~257之间的数字共用一份地址,范围可以修改

    name = ‘李璐’

    for i in name:

      print(i)   //将会打印出李璐

      print(bytes(i,encoding='utf-8'))   //把utf-8编码的字符转换成字节流

    --恢复内容开始---

    name1 = "wupeiqi"
    name2 = name1

    ---恢复内容结束---

    pycharm工具使用ctrl + /  可以批量注释

    1、查看对象的类,或对象所具备的功能

      temp = ‘ssss’

      dir(temp)  可以字符串类所有该功能

      help(temp) 或者help(type(temp))可以详细接受每种功能

    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 """

    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 """


    def count(self, sub, start=None, end=None):
    """ 子序列个数 """

    def decode(self, encoding=None, errors=None):
    """ 解码 """

    def encode(self, encoding=None, errors=None):
    """ 编码,针对unicode """

    def endswith(self, suffix, start=None, end=None):
    """ 是否以 xxx 结束 """

    def expandtabs(self, tabsize=None):
    """ 将tab转换成空格,默认一个tab转换成8个空格 """
         ‘hello 999’ -> ‘hello 999’

    def find(self, sub, start=None, end=None):
    """ 寻找子序列位置,如果没找到,返回 -1 """

    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 """
         'hello {0},age {1}'.format('alex',19) -> hello alex,age 19

    def index(self, sub, start=None, end=None):
    """ 子序列位置,如果没找到,报错 """

    def isalnum(self):
    """ 是否是字母和数字 """

    def isalpha(self):
    """ 是否是字母 """

    def isdigit(self):
    """ 是否是数字 """

    def islower(self):
    """ 是否小写 """

    def isspace(self):
        是否是空格

    def istitle(self):
        是否是标题(单词首字母是不是都大写)

    def isupper(self):
        是否大写

    def join(self, iterable):
    """ 连接 """
    b是列表或者元组 a.join(b) -> 把列表 b中每个元素用a连接起来


    def ljust(self, width, fillchar=None):
    """ 内容左对齐,右侧填充 """

    def lower(self):
    """ 变小写 """

    def lstrip(self, chars=None):
    """ 移除左侧空白 """

    def partition(self, sep):
    """ 分割,前,中,后三部分 """
    """
    S.partition(sep) -> (head, sep, tail)(元组)


    def replace(self, old, new, count=None):
    """ 替换 """
    """count表示从左往右替换多少个
    S.replace(old, new[, count]) -> string

    def rfind(self, sub, start=None, end=None):
    """从右往左找
    S.rfind(sub [,start [,end]]) -> int

    def rindex(self, sub, start=None, end=None):
    """

    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)

    def rsplit(self, sep=None, maxsplit=None):
    """
    S.rsplit([sep [,maxsplit]]) -> list of strings
    从左边开始分割

    def rstrip(self, chars=None):
    """把右边空白移除
    S.rstrip([chars]) -> string or unicode

    def split(self, sep=None, maxsplit=None):
    """ 分割, maxsplit最多分割几次 """
    """
    S.split([sep [,maxsplit]]) -> list of strings

    def splitlines(self, keepends=False):
    """ 根据换行分割 """
    """
    S.splitlines(keepends=False) -> list of strings


    def startswith(self, prefix, start=None, end=None):
    """ 是否已摸个字符或者字符串起始 """
    """
    S.startswith(prefix[, start[, end]]) -> bool


    def strip(self, chars=None):
    """ 移除两段空白 """
    """
    S.strip([chars]) -> string or unicode


    def swapcase(self):
    """ 大写变小写,小写变大写 """


    def title(self):
    """
    字符串”变成标题

    “the sheool” -> 'The School'

    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')
    """

    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<y """
    pass

    def __mod__(self, y):
    """ x.__mod__(y) <==> 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) """
    pass

    
    
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  • 原文地址:https://www.cnblogs.com/liusiluandzhangkun/p/10166057.html
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