Python基础语言学习笔记总结（精华）

Python  /  管理员 发布于 7年前   170

以下是Python基础学习内容的学习笔记的全部内容，非常的详细，如果你对Python语言感兴趣，并且针对性的系统学习一下基础语言知识，下面的内容能够很好的满足你的需求，如果感觉不错，就收藏以后慢慢跟着学习吧。

一、变量赋值及命名规则

① 声明一个变量及赋值

#!/usr/bin/env python# -*- coding:utf-8 -*-# _author_soloLiname1="solo"name2=name1print(name1,name2)name1 = "hehe"print(name1,name2)

#name1的值为hehe，name2的值为solo

② 变量命名的规则

1、变量名只能是 字母、数字或下划线的任意组合2、变量名的第一个字符不能是数字3、以下关键字不能声明为变量名['and', 'as', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'exec', 'finally', 'for', 'from', 'global','if', 'import', 'in', 'is', 'lambda', 'not', 'or', 'pass', 'print', 'raise', 'return', 'try', 'while', 'with', 'yield']

二、字符编码

python解释器在加载 .py 文件中的代码时，会对内容进行编码（默认ascill）

ASCII：最多只能用 8位来表示（一个字节），即：2**8 = 256，所以，ASCII码最多只能表示 256 个符号。显然ASCII码无法将世界上的各种文字和符号全部表示。

Unicode：它为每种语言中的每个字符设定了统一并且唯一的二进制编码，规定虽有的字符和符号最少由 16 位来表示（2个字节），即：2 **16 = 65536，注：此处说的的是最少2个字节，可能更多。

UTF-8：是对Unicode编码的压缩和优化，他不再使用最少使用2个字节，而是将所有的字符和符号进行分类：ascii码中的内容用1个字节保存、欧洲的字符用2个字节保存，东亚的字符用3个字节保存...
注：python2.x版本，默认支持的字符编码为ASCll python3.x版本，默认支持的是Unicode，不用声明字符编码可以直接显示中文。

 扩展：字符编码和转码，bytes和str区别

    Python 3最重要的新特性大概要算是对文本和二进制数据作了更为清晰的区分。文本总是Unicode，由str类型表示，二进制数据则由bytes类型表示。Python 3不会以任意隐式的方式混用str和bytes（类似int和long之间自动转换），正是这使得两者的区分特别清晰。你不能拼接字符串和字节包，也无法在字节包里搜索字符串（反之亦然），也不能将字符串传入参数为字节包的函数（反之亦然）。这是件好事。不管怎样，字符串和字节包之间的界线是必然的，下面的图解非常重要，务请牢记于心：

字符串可以编码成字节包，而字节包可以解码成字符串：

#!/usr/bin/env python# -*- coding:utf-8 -*-#-Author-solomsg = "里约奥运"print(msg.encode("utf-8"))           #如果不指定编码格式，默认为utf-8#b'\xe9\x87\x8c\xe7\xba\xa6\xe5\xa5\xa5\xe8\xbf\x90'print(b'\xe9\x87\x8c\xe7\xba\xa6\xe5\xa5\xa5\xe8\xbf\x90'.decode("utf-8"))#里约奥运

为什么要进行编码和转码？

　　由于每个国家电脑的字符编码格式不统一（列中国：GBK），同一款软件放到不同国家的电脑上会出现乱码的情况，出现这种情况如何解决呢？！ 当然由于所有国家的电脑都支持Unicode万国码，那么我们可以把Unicode为跳板，先把字符编码转换为Unicode，在把Unicode转换为另一个国家的字符编码（例韩国），则不会出现乱码的情况。当然这里只是转编码集并不是翻译成韩文不要弄混了。

① Python3.0进行编码转换（默认Unicode编码）

name = ""           #此时name为Unicode编码name1 = name.encode("utf-8")   #Unicode转为UTF-8name2 = name1.decode("utf-8")   #UTF-8转为Unicodename3 = name.encode("gbk")    #Unicode转为GBKname4 = name3.decode("gbk")   #GBK转为Unicode

② Python2.0中的编码转换（默认ascii编码）

① 声明字符编码（utf-8）# -*- coding:utf-8 -*-name = "李伟"          #ascii码里是没有字符“你好”的，此时的name为uft-8name1 = name.decode("utf-8")  #UTF-8转为Unicodename2 = name1.encode("gbk")   #Unicode转为gbk② 使用默认字符编码（ascii）name = "nihao"       #英文字符，且第二行字符声明去掉，此刻name为ascii码name1 = name.decode("ascii")   #ascii码转为unicodename2 = name1.encode("utf-8") #unicode转为utf-8name3 =name1.encode("gbk")   #unicode转为gbk

三、用户交互及字符串拼接

#!/usr/bin/env python# -*- coding:utf-8 -*-# _author_soloLi# python2.X与python3.X区别:  python2.X raw_input = python3.X input# 提示用户输入姓名、年龄、工作、工资并以信息列表的形式打印出name = input("Please input your name:")age = int(input("Please input your age:")) #str强制转换为intjob = input("Please input your job:")salary = input("Please input your salary:")info1 = '''------------ Info of %s ---------Name:%sAge:%dJob：%sSalary：%s''' %(name,name,age,job,salary)   #%s检测数据类型为字符串，%d检测数据类型为整数,%f检测数据类型为浮点数 强制print(info1)# info2 = '''# ------------ Info of {_Name} ---------# Name:{_Name}# Age:{_Age}# Job：{_Job}# Salary：{_Salary}# ''' .format(_Name=name,#       _Age=age,#       _Job=job,#       _Salary=salary)# print(info2)# info3 = '''# ------------ Info of {0} ---------# Name:{0}# Age:{1}# Job：{2}# Salary：{3}# ''' .format(name,age,job,salary)# print(info3)

对比分析：
1、% ：无法同时传递一个变量和元组，又是要加（）来保证不抛出typeerror异常
2、+ ：每增加一个一个+就会开辟一块新的内存空间
3、.fomat ：不会出现上述问题，有时使用为了兼容Python2版本。如使用logging库

四、循环语句（if、while、for、三元运算）

#!/usr/bin/env python# -*- coding:utf-8 -*-# _author_soloLi################## if语句 ####################### A = 66## B = int(input("请输入0-100的幸运数字:"))## if B == A:           #母级顶格写#   print ("恭喜你猜对了!")  #子级强制缩进写# elif B > A :#   print ("猜小了")# else:#   print ("猜大了")################## while语句 ####################### A = 66# count = 0          # 设置初始值count=0## while count < 3 :##   B = int(input("请输入0-100的数字:"))##   if B == A:#     print ("恭喜你猜对了!")#     break#   elif B > A :#     print ("猜大了")#   else:#     print ("猜小了")#   count += 1# else:#   print ("你猜的次数太多了!")################## for语句 ######################A = 66i=1for i in range(3):# while判断count是否小于3，如果小于3则：  print("i=",i)  B = int(input("请输入0-100的数字:"))  if B == A:    print ("恭喜你猜对了!")    break  elif B > A :    print ("猜小了")  else:    print ("猜大了")  i+=1else:  print ("你猜的次数太多了!")################## 三元运算 ###################### # esult = 值1 if 条件 else 值2 # 如果条件成立，那么将 “值1” 赋值给result变量，否则，将“值2”赋值给result变量

五、基本数据类型

一、整型
如： 18、73、84
类型常用功能：

abs(x)   #返回绝对值x+y,x-y,x*y,x/y #加减乘除x/y     #取商，浮点数相除保留余数x//y    #取商，浮点数相除余数为0x%y     #取余x**y     #幂次方cmp(x,y)  #两个数比较，返回True或False相等则为0coerce(x,y) #强制把两个数生成一个元组divmod(x,y) #相除得到商和余数组成的元组float(x)  #转换为浮点型str(x)   #转换为字符串hex(x)   #转换为16进制oct(x)   #转换8进制

更多功能：

class int(object):  """  int(x=0) -> int or long  int(x, base=10) -> int or long    Convert a number or string to an integer, or return 0 if no arguments  are given. If x is floating point, the conversion truncates towards zero.  If x is outside the integer range, the function returns a long instead.    If x is not a number or if base is given, then x must be a string or  Unicode object representing an integer literal in the given base. The  literal can be preceded by '+' or '-' and be surrounded by whitespace.  The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to  interpret the base from the string as an integer literal.  >>> int('0b100', base=0)  """  def bit_length(self):     """ 返回表示该数字的时占用的最少位数 """    """    int.bit_length() -> int        Number of bits necessary to represent self in binary.    >>> bin(37)    '0b100101'    >>> (37).bit_length()    """    return 0  def conjugate(self, *args, **kwargs): # real signature unknown    """ 返回该复数的共轭复数 """    """ Returns self, the complex conjugate of any int. """    pass  def __abs__(self):    """ 返回绝对值 """    """ x.__abs__() <==> abs(x) """    pass  def __add__(self, y):    """ x.__add__(y) <==> x+y """    pass  def __and__(self, y):    """ x.__and__(y) <==> x&y """    pass  def __cmp__(self, y):     """ 比较两个数大小 """    """ x.__cmp__(y) <==> cmp(x,y) """    pass  def __coerce__(self, y):    """ 强制生成一个元组 """     """ x.__coerce__(y) <==> coerce(x, y) """    pass  def __divmod__(self, y):     """ 相除，得到商和余数组成的元组 """     """ x.__divmod__(y) <==> divmod(x, y) """    pass  def __div__(self, y):     """ x.__div__(y) <==> x/y """    pass  def __float__(self):     """ 转换为浮点类型 """     """ x.__float__() <==> float(x) """    pass  def __floordiv__(self, y):     """ x.__floordiv__(y) <==> x//y """    pass  def __format__(self, *args, **kwargs): # real signature unknown    pass  def __getattribute__(self, name):     """ x.__getattribute__('name') <==> x.name """    pass  def __getnewargs__(self, *args, **kwargs): # real signature unknown    """ 内部调用 __new__方法或创建对象时传入参数使用 """     pass  def __hash__(self):     """如果对象object为哈希表类型，返回对象object的哈希值。哈希值为整数。在字典查找中，哈希值用于快速比较字典的键。两个数值如果相等，则哈希值也相等。"""    """ x.__hash__() <==> hash(x) """    pass  def __hex__(self):     """ 返回当前数的 十六进制 表示 """     """ x.__hex__() <==> hex(x) """    pass  def __index__(self):     """ 用于切片，数字无意义 """    """ x[y:z] <==> x[y.__index__():z.__index__()] """    pass  def __init__(self, x, base=10): # known special case of int.__init__    """ 构造方法，执行 x = 123 或 x = int(10) 时，自动调用，暂时忽略 """     """    int(x=0) -> int or long    int(x, base=10) -> int or long        Convert a number or string to an integer, or return 0 if no arguments    are given. If x is floating point, the conversion truncates towards zero.    If x is outside the integer range, the function returns a long instead.        If x is not a number or if base is given, then x must be a string or    Unicode object representing an integer literal in the given base. The    literal can be preceded by '+' or '-' and be surrounded by whitespace.    The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to    interpret the base from the string as an integer literal.    >>> int('0b100', base=0)    # (copied from class doc)    """    pass  def __int__(self):     """ 转换为整数 """     """ x.__int__() <==> int(x) """    pass  def __invert__(self):     """ x.__invert__() <==> ~x """    pass  def __long__(self):     """ 转换为长整数 """     """ x.__long__() <==> long(x) """    pass  def __lshift__(self, y):     """ x.__lshift__(y) <==> x<<y """    pass  def __mod__(self, y):     """ x.__mod__(y) <==> x%y """    pass  def __mul__(self, y):     """ x.__mul__(y) <==> x*y """    pass  def __neg__(self):     """ x.__neg__() <==> -x """    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 __nonzero__(self):     """ x.__nonzero__() <==> x != 0 """    pass  def __oct__(self):     """ 返回改值的 八进制 表示 """     """ x.__oct__() <==> oct(x) """    pass  def __or__(self, y):     """ x.__or__(y) <==> x|y """    pass  def __pos__(self):     """ x.__pos__() <==> +x """    pass  def __pow__(self, y, z=None):     """ 幂，次方 """     """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """    pass  def __radd__(self, y):     """ x.__radd__(y) <==> y+x """    pass  def __rand__(self, y):     """ x.__rand__(y) <==> y&x """    pass  def __rdivmod__(self, y):     """ x.__rdivmod__(y) <==> divmod(y, x) """    pass  def __rdiv__(self, y):     """ x.__rdiv__(y) <==> y/x """    pass  def __repr__(self):     """转化为解释器可读取的形式 """    """ x.__repr__() <==> repr(x) """    pass  def __str__(self):     """转换为人阅读的形式，如果没有适于人阅读的解释形式的话，则返回解释器课阅读的形式"""    """ x.__str__() <==> str(x) """    pass  def __rfloordiv__(self, y):     """ x.__rfloordiv__(y) <==> y//x """    pass  def __rlshift__(self, y):     """ x.__rlshift__(y) <==> y<<x """    pass  def __rmod__(self, y):     """ x.__rmod__(y) <==> y%x """    pass  def __rmul__(self, y):     """ x.__rmul__(y) <==> y*x """    pass  def __ror__(self, y):     """ x.__ror__(y) <==> y|x """    pass  def __rpow__(self, x, z=None):     """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """    pass  def __rrshift__(self, y):     """ x.__rrshift__(y) <==> y>>x """    pass  def __rshift__(self, y):     """ x.__rshift__(y) <==> x>>y """    pass  def __rsub__(self, y):     """ x.__rsub__(y) <==> y-x """    pass  def __rtruediv__(self, y):     """ x.__rtruediv__(y) <==> y/x """    pass  def __rxor__(self, y):     """ x.__rxor__(y) <==> y^x """    pass  def __sub__(self, y):     """ x.__sub__(y) <==> x-y """    pass  def __truediv__(self, y):     """ x.__truediv__(y) <==> x/y """    pass  def __trunc__(self, *args, **kwargs):     """ 返回数值被截取为整形的值，在整形中无意义 """    pass  def __xor__(self, y):     """ x.__xor__(y) <==> x^y """    pass  denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """ 分母 = 1 """  """the denominator of a rational number in lowest terms"""  imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """ 虚数，无意义 """  """the imaginary part of a complex number"""  numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """ 分子 = 数字大小 """  """the numerator of a rational number in lowest terms"""  real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """ 实属，无意义 """  """the real part of a complex number"""intint

二、长整型
如：2147483649、9223372036854775807
类型常用功能：

#长整型功能与整形基本类似

class long(object):  """  long(x=0) -> long  long(x, base=10) -> long    Convert a number or string to a long integer, or return 0L if no arguments  are given. If x is floating point, the conversion truncates towards zero.    If x is not a number or if base is given, then x must be a string or  Unicode object representing an integer literal in the given base. The  literal can be preceded by '+' or '-' and be surrounded by whitespace.  The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to  interpret the base from the string as an integer literal.  >>> int('0b100', base=0)  4L  """  def bit_length(self): # real signature unknown; restored from __doc__    """    long.bit_length() -> int or long        Number of bits necessary to represent self in binary.    >>> bin(37L)    '0b100101'    >>> (37L).bit_length()    """    return 0  def conjugate(self, *args, **kwargs): # real signature unknown    """ Returns self, the complex conjugate of any long. """    pass  def __abs__(self): # real signature unknown; restored from __doc__    """ x.__abs__() <==> abs(x) """    pass  def __add__(self, y): # real signature unknown; restored from __doc__    """ x.__add__(y) <==> x+y """    pass  def __and__(self, y): # real signature unknown; restored from __doc__    """ x.__and__(y) <==> x&y """    pass  def __cmp__(self, y): # real signature unknown; restored from __doc__    """ x.__cmp__(y) <==> cmp(x,y) """    pass  def __coerce__(self, y): # real signature unknown; restored from __doc__    """ x.__coerce__(y) <==> coerce(x, y) """    pass  def __divmod__(self, y): # real signature unknown; restored from __doc__    """ x.__divmod__(y) <==> divmod(x, y) """    pass  def __div__(self, y): # real signature unknown; restored from __doc__    """ x.__div__(y) <==> x/y """    pass  def __float__(self): # real signature unknown; restored from __doc__    """ x.__float__() <==> float(x) """    pass  def __floordiv__(self, y): # real signature unknown; restored from __doc__    """ x.__floordiv__(y) <==> x//y """    pass  def __format__(self, *args, **kwargs): # real signature unknown    pass  def __getattribute__(self, name): # real signature unknown; restored from __doc__    """ x.__getattribute__('name') <==> x.name """    pass  def __getnewargs__(self, *args, **kwargs): # real signature unknown    pass  def __hash__(self): # real signature unknown; restored from __doc__    """ x.__hash__() <==> hash(x) """    pass  def __hex__(self): # real signature unknown; restored from __doc__    """ x.__hex__() <==> hex(x) """    pass  def __index__(self): # real signature unknown; restored from __doc__    """ x[y:z] <==> x[y.__index__():z.__index__()] """    pass  def __init__(self, x=0): # real signature unknown; restored from __doc__    pass  def __int__(self): # real signature unknown; restored from __doc__    """ x.__int__() <==> int(x) """    pass  def __invert__(self): # real signature unknown; restored from __doc__    """ x.__invert__() <==> ~x """    pass  def __long__(self): # real signature unknown; restored from __doc__    """ x.__long__() <==> long(x) """    pass  def __lshift__(self, y): # real signature unknown; restored from __doc__    """ x.__lshift__(y) <==> x<<y """    pass  def __mod__(self, y): # real signature unknown; restored from __doc__    """ x.__mod__(y) <==> x%y """    pass  def __mul__(self, y): # real signature unknown; restored from __doc__    """ x.__mul__(y) <==> x*y """    pass  def __neg__(self): # real signature unknown; restored from __doc__    """ x.__neg__() <==> -x """    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 __nonzero__(self): # real signature unknown; restored from __doc__    """ x.__nonzero__() <==> x != 0 """    pass  def __oct__(self): # real signature unknown; restored from __doc__    """ x.__oct__() <==> oct(x) """    pass  def __or__(self, y): # real signature unknown; restored from __doc__    """ x.__or__(y) <==> x|y """    pass  def __pos__(self): # real signature unknown; restored from __doc__    """ x.__pos__() <==> +x """    pass  def __pow__(self, y, z=None): # real signature unknown; restored from __doc__    """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """    pass  def __radd__(self, y): # real signature unknown; restored from __doc__    """ x.__radd__(y) <==> y+x """    pass  def __rand__(self, y): # real signature unknown; restored from __doc__    """ x.__rand__(y) <==> y&x """    pass  def __rdivmod__(self, y): # real signature unknown; restored from __doc__    """ x.__rdivmod__(y) <==> divmod(y, x) """    pass  def __rdiv__(self, y): # real signature unknown; restored from __doc__    """ x.__rdiv__(y) <==> y/x """    pass  def __repr__(self): # real signature unknown; restored from __doc__    """ x.__repr__() <==> repr(x) """    pass  def __rfloordiv__(self, y): # real signature unknown; restored from __doc__    """ x.__rfloordiv__(y) <==> y//x """    pass  def __rlshift__(self, y): # real signature unknown; restored from __doc__    """ x.__rlshift__(y) <==> y<<x """    pass  def __rmod__(self, y): # real signature unknown; restored from __doc__    """ x.__rmod__(y) <==> y%x """    pass  def __rmul__(self, y): # real signature unknown; restored from __doc__    """ x.__rmul__(y) <==> y*x """    pass  def __ror__(self, y): # real signature unknown; restored from __doc__    """ x.__ror__(y) <==> y|x """    pass  def __rpow__(self, x, z=None): # real signature unknown; restored from __doc__    """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """    pass  def __rrshift__(self, y): # real signature unknown; restored from __doc__    """ x.__rrshift__(y) <==> y>>x """    pass  def __rshift__(self, y): # real signature unknown; restored from __doc__    """ x.__rshift__(y) <==> x>>y """    pass  def __rsub__(self, y): # real signature unknown; restored from __doc__    """ x.__rsub__(y) <==> y-x """    pass  def __rtruediv__(self, y): # real signature unknown; restored from __doc__    """ x.__rtruediv__(y) <==> y/x """    pass  def __rxor__(self, y): # real signature unknown; restored from __doc__    """ x.__rxor__(y) <==> y^x """    pass  def __sizeof__(self, *args, **kwargs): # real signature unknown    """ Returns size in memory, in bytes """    pass  def __str__(self): # real signature unknown; restored from __doc__    """ x.__str__() <==> str(x) """    pass  def __sub__(self, y): # real signature unknown; restored from __doc__    """ x.__sub__(y) <==> x-y """    pass  def __truediv__(self, y): # real signature unknown; restored from __doc__    """ x.__truediv__(y) <==> x/y """    pass  def __trunc__(self, *args, **kwargs): # real signature unknown    """ Truncating an Integral returns itself. """    pass  def __xor__(self, y): # real signature unknown; restored from __doc__    """ x.__xor__(y) <==> x^y """    pass  denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the denominator of a rational number in lowest terms"""  imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the imaginary part of a complex number"""  numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the numerator of a rational number in lowest terms"""  real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the real part of a complex number"""longlong

注：跟C语言不同，Python的长整数没有指定位宽，即：Python没有限制长整数数值的大小，但实际上由于机器内存有限，我们使用的长整数数值不可能无限大。自从Python2.2起，如果整数发生溢出，Python会自动将整数数据转换为长整数，所以如今在长整数数据后面不加字母L也不会导致严重后果

三、浮点型
如：3.14、2.88

类型常用功能：

#浮点型功能与整形基本类似

class float(object):  """  float(x) -> floating point number    Convert a string or number to a floating point number, if possible.  """  def as_integer_ratio(self):      """ 获取改值的最简比 """    """    float.as_integer_ratio() -> (int, int)    Return a pair of integers, whose ratio is exactly equal to the original    float and with a positive denominator.    Raise OverflowError on infinities and a ValueError on NaNs.    >>> (10.0).as_integer_ratio()    (10, 1)    >>> (0.0).as_integer_ratio()    (0, 1)    >>> (-.25).as_integer_ratio()    (-1, 4)    """    pass  def conjugate(self, *args, **kwargs): # real signature unknown    """ Return self, the complex conjugate of any float. """    pass  def fromhex(self, string):      """ 将十六进制字符串转换成浮点型 """    """    float.fromhex(string) -> float        Create a floating-point number from a hexadecimal string.    >>> float.fromhex('0x1.ffffp10')    2047.984375    >>> float.fromhex('-0x1p-1074')    -4.9406564584124654e-324    """    return 0.0  def hex(self):      """ 返回当前值的 16 进制表示 """    """    float.hex() -> string        Return a hexadecimal representation of a floating-point number.    >>> (-0.1).hex()    '-0x1.999999999999ap-4'    >>> 3.14159.hex()    '0x1.921f9f01b866ep+1'    """    return ""  def is_integer(self, *args, **kwargs): # real signature unknown    """ Return True if the float is an integer. """    pass  def __abs__(self):      """ x.__abs__() <==> abs(x) """    pass  def __add__(self, y):      """ x.__add__(y) <==> x+y """    pass  def __coerce__(self, y):      """ x.__coerce__(y) <==> coerce(x, y) """    pass  def __divmod__(self, y):      """ x.__divmod__(y) <==> divmod(x, y) """    pass  def __div__(self, y):      """ x.__div__(y) <==> x/y """    pass  def __eq__(self, y):      """ x.__eq__(y) <==> x==y """    pass  def __float__(self):      """ x.__float__() <==> float(x) """    pass  def __floordiv__(self, y):      """ x.__floordiv__(y) <==> x//y """    pass  def __format__(self, format_spec):      """    float.__format__(format_spec) -> string        Formats the float according to format_spec.    """    return ""  def __getattribute__(self, name):      """ x.__getattribute__('name') <==> x.name """    pass  def __getformat__(self, typestr):      """    float.__getformat__(typestr) -> string        You probably don't want to use this function. It exists mainly to be    used in Python's test suite.        typestr must be 'double' or 'float'. This function returns whichever of    'unknown', 'IEEE, big-endian' or 'IEEE, little-endian' best describes the    format of floating point numbers used by the C type named by typestr.    """    return ""  def __getnewargs__(self, *args, **kwargs): # real signature unknown    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, x):      pass  def __int__(self):      """ x.__int__() <==> int(x) """    pass  def __le__(self, y):      """ x.__le__(y) <==> x<=y """    pass  def __long__(self):      """ x.__long__() <==> long(x) """    pass  def __lt__(self, y):      """ x.__lt__(y) <==> x<y """    pass  def __mod__(self, y):      """ x.__mod__(y) <==> x%y """    pass  def __mul__(self, y):      """ x.__mul__(y) <==> x*y """    pass  def __neg__(self):      """ x.__neg__() <==> -x """    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 __nonzero__(self):      """ x.__nonzero__() <==> x != 0 """    pass  def __pos__(self):      """ x.__pos__() <==> +x """    pass  def __pow__(self, y, z=None):      """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """    pass  def __radd__(self, y):      """ x.__radd__(y) <==> y+x """    pass  def __rdivmod__(self, y):      """ x.__rdivmod__(y) <==> divmod(y, x) """    pass  def __rdiv__(self, y):      """ x.__rdiv__(y) <==> y/x """    pass  def __repr__(self):      """ x.__repr__() <==> repr(x) """    pass  def __rfloordiv__(self, y):      """ x.__rfloordiv__(y) <==> y//x """    pass  def __rmod__(self, y):      """ x.__rmod__(y) <==> y%x """    pass  def __rmul__(self, y):      """ x.__rmul__(y) <==> y*x """    pass  def __rpow__(self, x, z=None):      """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """    pass  def __rsub__(self, y):      """ x.__rsub__(y) <==> y-x """    pass  def __rtruediv__(self, y):      """ x.__rtruediv__(y) <==> y/x """    pass  def __setformat__(self, typestr, fmt):      """    float.__setformat__(typestr, fmt) -> None        You probably don't want to use this function. It exists mainly to be    used in Python's test suite.        typestr must be 'double' or 'float'. fmt must be one of 'unknown',    'IEEE, big-endian' or 'IEEE, little-endian', and in addition can only be    one of the latter two if it appears to match the underlying C reality.        Override the automatic determination of C-level floating point type.    This affects how floats are converted to and from binary strings.    """    pass  def __str__(self):      """ x.__str__() <==> str(x) """    pass  def __sub__(self, y):      """ x.__sub__(y) <==> x-y """    pass  def __truediv__(self, y):      """ x.__truediv__(y) <==> x/y """    pass  def __trunc__(self, *args, **kwargs): # real signature unknown    """ Return the Integral closest to x between 0 and x. """    pass  imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the imaginary part of a complex number"""  real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default  """the real part of a complex number""" floatfloat

四、字符串
如：'wupeiqi'、'alex'、'solo'

类型常用功能：

name = "my name is solo"print(name.capitalize())      #首字母大写#My name is soloprint(name.count("l"))       #统计字符串出现某个字符的个数#2print(name.center(30,"-"))     #打印30个字符，不够的-补齐#--------my name is solo--------print(name.ljust(30,"-"))      #打印30个字符，不够的-补齐，字符串在左边#my name is solo----------------print(name.endswith("solo"))     #判断字符串是否以solo结尾#Trueprint(name[name.find("na"):])    #find寻找na所在的索引下标 字符串也可以切片#name is soloprint("5.3".isdigit())       #判断字符是否为整数#Falseprint("a_1A".isidentifier())    #判断是不是一个合法的标识符（变量名）#Trueprint("+".join(["1","2","3"]))   #把join后的内容加入到前面字符串中，以+为分割符#1+2+3print("\nsolo".strip())       #去换行符#soloprint("1+2+3+4".split("+"))    #以+为分隔符生成新的列表，默认不写为空格#['1', '2', '3', '4']name = "my name is {name} and i an {year} old"print(name.format(name="solo",year=20)#my name is solo and i an 20 oldprint(name.format_map({"name":"solo","year":20}))      #很少用#my name is solo and i an 20 oldp = str.maketrans("abcdefli","12345678")     #转换 一一对应print("lianzhilei".translate(p))#781nzh8758

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