标准类型数字
字符串列表
元组
字典其他类型
类型type
Null
⽂件
集合
函数／⽅法
类
模块
基本数据类型（数字字符串）
1.python中的数据类型
  python使⽤对象模型来存储数据，每⼀个数据类型都有⼀个内置的类，每新建⼀个数据，实际就是在初始化⽣成⼀个对象，即所有数据都是对象。  对象的三个特性
⾝份：内存地址，可以⽤id()获取
类型：决定了该对象可以保存什么类型值，可执⾏何种操作，需遵循什么规则，可⽤type()获取
值：对象保存的真实数据
  注：我们在定义数据类型，只需这样：x＝1，内部⽣成数字类型1这⼀内存对象会⾃动触发，我们⽆需关⼼
  数据类型
  这⾥的字符串、数字、列表等都是数据类型，除此之外还有很多其他数据，处理不同的数据就需要定义不同的数据类型。
2.标准数据类型
　2.1 数字
定义：a＝1
特性：
1.只能存放⼀个值
2.⼀经定义，不可更改
3.直接访问
分类：整型，长整型，布尔，浮点，复数
2.1.1 整形
    Python中的整数属于int类型，默认⽤⼗进制表⽰，此外也⽀持⼆进制，⼋进制,⼗六进制表⽰⽅式。
>>> 10
10            --------->默认⼗进制
>>> bin(10)
'0b1010'      --------->⼆进制表⽰整数时，数值前⾯要加上⼀个前缀“0b”
>>> oct(10)
'012'        --------->⼋进制表⽰整数时，数值前⾯要加上⼀个前缀“0”
>>> hex(10)
'0xa'        --------->⼗六进制表⽰整数时，数字前⾯要加上前缀0X或0x
  python2.*与python3.*
关于整型的区别：
python2.*
  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
python3.*
  整⾏长度⽆限制
py2与py3整型长度约束
2.1.2 bool型
    bool型只有两个值：True和False
    之所以将bool值归类为数字，是因为我们也习惯⽤1表⽰True，0表⽰False。
2.1.3 float型
  Python的浮点数就是数学中的⼩数。
在运算中，整数与浮点数运算的结果也是⼀个浮点数。
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，1.23*109和12.3*108是相等的。
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，1.23*109就是1.23e9，或者12.3e8，0.000012
可以写成1.2e-5，等等。
整数和浮点数在计算机内部存储的⽅式是不同的，整数运算永远是精确的⽽浮点数运算则可能会有
四舍五⼊的误差。
⼩数为什么叫做浮点数？
2.1.4 comple型
  复数由实数部分和虚数部分组成，⼀般形式为x＋yj，其中的x是复数的实数部分，y是复数的虚数部分，这⾥的x和y都是实数。  注，虚数部分的字母j⼤⼩写都可以。 
>>> 1.3 + 2.5j == 1.3 + 2.5J
True
2.1.5 数字相关内建函数
2.2 字符串
2.2.1 定义与特性
  字符串是⼀个有序的字符的集合，⽤于存储和表⽰基本的⽂本信息，' '或'' ''或''' '''中间包含的内容称之为字符串
  特性：
    1.只能存放⼀个值
    2.不可变
    3.按照从左到右的顺序定义字符集合，下标从0开始顺序访问，有序
  补充：
    1.字符串的单引号和双引号都⽆法取消特殊字符的含义，如果想让引号内所有字符均取消特殊意义，在引号前⾯加r，如name＝r'l\thf'
    2.unicode字符串与r连⽤必需在r前⾯，如name＝ur'l\thf'
2.2.2 字符串的创建与常⽤操作
    创建：
      s = 'Hello,Eva！How are you?'
    常⽤操作：
      索引
      切⽚
      移除空⽩ strip
      ⼤⼩写转换upper/lower
      替换replace
      分割 split
      包含 startswith/endswith/index/find
      判断成分 isdigit/isalpha
    　计算长度 len函数
2.2.3  str字符串⼯⼚函数
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 defaultencoding().
errors defaults to 'strict'.
</span><span >"""</span>
<span >def</span> capitalize(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
⾸字母变⼤写
S.capitalize() -> str
Return a capitalized version of S, i.e. make the first character
have upper case and the rest lower case.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> casefold(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
S.casefold() -> str
Return a version of S suitable for caseless comparisons.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> center(self, width, fillchar=None): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
原来字符居中，不够⽤空格补全
<(width[, fillchar]) -> str
Return S centered in a string of length width. Padding is
done using the specified fill character (default is a space)
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> count(self, sub, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
从⼀个范围内的统计某str出现次数
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.
</span><span >"""</span>
<span >return</span><span > 0
</span><span >def</span> encode(self, encoding=<span >'</span><span >utf-8</span><span >'</span>, errors=<span color: #800000;">"""</span><span >
encode(encoding='utf-8',errors='strict')
以encoding指定编码格式编码，如果出错默认报⼀个ValueError，除⾮errors指定的是
ignore或replace
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
</span><span >"""</span>
<span >return</span> b<span >""</span>
<span >def</span> endswith(self, suffix, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> expandtabs(self, tabsize=8): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
将字符串中包含的\t转换成tabsize个空格
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.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> find(self, sub, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span><span > 0
</span><span >def</span> format(self, *args, **kwargs): <span >#</span><span > known special case of str.format</span>
<span >"""</span><span >
格式化输出
三种形式：
形式⼀.
>>> print('{0}{1}{0}'.format('a','b'))
aba
形式⼆：（必须⼀⼀对应）
>>> 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 '}').
</span><span >"""</span>
<span >pass</span>
<span >def</span> format_map(self, mapping): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
与format区别
'{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 '}').
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> index(self, sub, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
S.index(sub[, start[, end]]) -> int
Like S.find() but raise ValueError when the substring is not found.
</span><span >"""</span>
<span >return</span><span > 0
</span><span >def</span> isalnum(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
⾄少⼀个字符，且都是字母或数字才返回True
S.isalnum() -> bool
Return True if all characters in S are alphanumeric
and there is at least one character in S, False otherwise.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isalpha(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
⾄少⼀个字符，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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isdecimal(self): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
S.isdecimal() -> bool
Return True if there are only decimal characters in S,
False otherwise.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isdigit(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
S.isdigit() -> bool
Return True if all characters in S are digits
and there is at least one character in S, False otherwise.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isidentifier(self): <span >#</span><span > real signature unknown; restored from __doc__</span>    <s
pan >"""</span><span >
字符串为关键字返回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".
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> islower(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
⾄少⼀个字符，且都是⼩写字母才返回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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isnumeric(self): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
S.isnumeric() -> bool
Return True if there are only numeric characters in S,
False otherwise.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isprintable(self): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
S.isprintable() -> bool
Return True if all characters in S are considered
printable in repr() or S is empty, False otherwise.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isspace(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
⾄少⼀个字符，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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> istitle(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
>>> 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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> isupper(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span><span > False
</span><span >def</span> join(self, iterable): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
#对序列进⾏操作（分别使⽤' '与':'作为分隔符）
>>> seq1 = ['hello','good','boy','doiido']
>>> print ' '.join(seq1)
hello good boy doiido
>>> print ':'.join(seq1)
hello:good:boy:doiido
#对字符串进⾏操作
>>> 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
#对元组进⾏操作
>>> seq3 = ('hello','good','boy','doiido')
>>> print ':'.join(seq3)
hello:good:boy:doiido
#对字典进⾏操作
>>> seq4 = {'hello':1,'good':2,'boy':3,'doiido':4}
>>> print ':'.join(seq4)
boy:good:doiido:hello
#合并⽬录
>>> 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.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> ljust(self, width, fillchar=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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).
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> lower(self): <span >#</span><span > real signature unknown; restored from __doc__</span>
index复数<span >"""</span><span >
S.lower() -> str
Return a copy of the string S converted to lowercase.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> lstrip(self, chars=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> maketrans(self, *args, **kwargs): <span >#</span><span > real signature unknown</span>
<span >"""</span><span >
Return a translation table usable anslate().
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.
</span><span >"""</span>
<span >pass</span>
<span >def</span> partition(self, sep): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
以sep为分割，将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.
</span><span >"""</span>
<span >pass</span>
<span >def</span> replace(self, old, new, count=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> rfind(self, sub, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >return</span><span > 0
</span><span >def</span> rindex(self, sub, start=None, end=None): <span >#</span><span > real signature unknown; restored from __doc__</span>    <span >"""</span><span >
S.rindex(sub[, start[, end]]) -> int
Like S.rfind() but raise ValueError when the substring is not found.
</span><span >"""</span>
<span >return</span><span > 0
</span><span >def</span> rjust(self, width, fillchar=None): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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).
</span><span >"""</span>
<span >return</span> <span >""</span>
<span >def</span> rpartition(self, sep): <span >#</span><span > real signature unknown; restored from __doc__</span>
<span >"""</span><span >
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.
</span><span >"""</span>
<span >pass</span>

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