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Python基础语言学习笔记总结(精华)

2017年11月17日 09:19  | 萬仟网IT编程  | 我要评论

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_soloLi
name1="solo"
name2=name1
print(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-solo
msg = "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 = "萬仟网"           #此时name为Unicode编码
name1 = name.encode("utf-8")   #Unicode转为UTF-8
name2 = name1.decode("utf-8")   #UTF-8转为Unicode
name3 = name.encode("gbk")    #Unicode转为GBK
name4 = 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-8
name1 = name.decode("utf-8")  #UTF-8转为Unicode
name2 = name1.encode("gbk")   #Unicode转为gbk
② 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unicode
name2 = name1.encode("utf-8") #unicode转为utf-8
name3 =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int
job = input("Please input your job:")
salary = input("Please input your salary:")
info1 = '''
------------ Info of %s ---------
Name:%s
Age:%d
Job:%s
Salary:%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 = 66
i=1
for 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+=1
else:
  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0
x%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0
coerce(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"""

int

int

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"""

long

long

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"""

 float

float

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 solo
print(name.count("l"))       #统计字符串出现某个字符的个数
#2
print(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
#True
print(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 solo
print("5.3".isdigit())       #判断字符是否为整数
#False
print("a_1A".isidentifier())    #判断是不是一个合法的标识符(变量名)
#True
print("+".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+3
print("\nsolo".strip())       #去换行符
#solo
print("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 old
print(name.format_map({"name":"solo","year":20}))      #很少用
#my name is solo and i an 20 old
p = 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 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<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

str

str

五、列表


如:[11,22,33,44,55]、['wupeiqi', 'alex','solo']
1、创建列表:

#两种创建方式
name_list = ['alex', 'seven', 'eric']
name_list = list(['alex', 'seven', 'eric'])

2、列表类常用功能:
① 切片

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
print(name_list[0:3])    #取下标0至下标3之间的元素,包括0,不包括3
#['Alex', 'Tenglan', 'Eric']
print(name_list[:3])    #:前什么都不写,表示从0开始,效果跟上句一样
#['Alex', 'Tenglan', 'Eric']
print(name_list[3:])    #:后什么不写,表示取值到最后
#['Rain', 'Tom', 'Amy']
print(name_list[:])     #:前后都不写,表示取值所有
#['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy']
print(name_list[-3:-1])   #从-3开始到-1,包括-3,不包括-1
#['Rain', 'Tom']
print(name_list[1:-1])   #从1开始到-1,下标有正有负时,正数在前负数在后
#['Tenglan', 'Eric', 'Rain', 'Tom']
print(name_list[::2])    #2表示,每个1个元素,就取一个
#['Alex', 'Eric', 'Tom']
#注:[-1:0] [0:0] [-1:2] 都是空

② 追加

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
name_list.append("new")     #append追加,加到最后,只能添加一个
print(name_list)
#['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', 'new']

③ 插入

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
name_list.insert(3,"new")     #insert插入,把"new"加到下标3的位置
print(name_list)

④ 修改

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
name_list[2] = "solo"        #把下标2的字符串换成solo
print(name_list)

⑤ 删除

#3种删除方式
name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
del name_list[3]           #del删除,指定要删除的下标
print(name_list)
#['Alex', 'Tenglan', 'Eric', 'Tom', 'Amy']
name_list.remove("Tenglan")     #remove删除,指定要删除的字符
print(name_list)
#['Alex', 'Eric', 'Tom', 'Amy']
name_list.pop()            #pop删除,删除列表最后一个值
print(name_list)
#['Alex', 'Eric', 'Tom']

⑥ 扩展

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
age_list = [11,22,33]
name_list.extend(age_list)        #extend扩展,把列表age_list添加到name_list列表
print(name_list)

⑦ 拷贝

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
copy_list = name_list.copy()        #copy拷贝,对列表进行复制
print(copy_list)
#注:之后会整理深浅copy的详细区分

⑧ 统计

name_list = ["Alex","Tenglan","Eric","Amy","Tom","Amy"]
print(name_list.count("Amy"))        #count统计,统计列表Amy的个数
#2

⑨ 排序和翻转

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy","1","2","3"]
name_list.sort()               #sort排序,对列表进行排序
print(name_list)
#['1', '2', '3', 'Alex', 'Amy', 'Eric', 'Rain', 'Tenglan', 'Tom']
name_list.reverse()              #reverse翻转,对列表进行翻转
print(name_list)
#['Tom', 'Tenglan', 'Rain', 'Eric', 'Amy', 'Alex', '3', '2', '1']

⑩ 获取下标

name_list = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
print(name_list.index("Tenglan"))       #index索引,获取字符的下标
#1

六、元组

如:(11,22,33,44,55)、('wupeiqi', 'alex','lzl')

1、创建元组:

#5种创建方式
age = 11,22,33,44,55      #直接写数字或者字符串,默认创建类型元组 字符串类型用引号'solo'
#输出: (11, 22, 33, 44, 55)  
age = (11,22,33,44,55)     #常见命名方式,()指定类型元组
#输出: (11, 22, 33, 44, 55)
age = tuple((11,22,33,44,55))  #tuple 以类的方式创建(()) 双括号 里面的()不可去掉
#输出: (11, 22, 33, 44, 55)
age = tuple([11,22,33,44,55])  #同(()) 效果一样 很少用 忘记它
#输出: (11, 22, 33, 44, 55)
age = tuple({11,22,33,44,55})  #({})创建的元组,随机排列 没卵用
#输出: (33, 11, 44, 22, 55)

2、元组类常用功能:

##count        #统计元组字符出现的次数   
name = ('wupeiqi', 'alex','solo')
print(name.count('alex'))       
# 1
##index       #查看字符串所在的索引位置
name = ('wupeiqi', 'alex','solo')
print(name.index('solo'))        
# solo

七、字典 无序


如:{'name': 'wupeiqi', 'age': 18} 、{'host': 'solo.solo.solo.solo', 'port': 80}
注:字典一种key:value 的数据类型,也称键值对。字典dict是无序的,key值必须是唯一的,不能有重复。循环时,默认循环的是key
 1、创建字典

#两种创建方式:
info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
print(info_dic)
#{'stu1102': 'LongZe Luola', 'stu1101': 'TengLan Wu', 'stu1103': 'XiaoZe Maliya'}
info_dic = dict({'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",})
print(info_dic)
#{'stu1102': 'LongZe Luola', 'stu1101': 'TengLan Wu', 'stu1103': 'XiaoZe Maliya'}

2、字典类常用功能:

① 增加

info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
info_dic['stu1104'] = "JingKong Cang"      #增加
print(info_dic)

② 修改

info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
info_dic["stu1101"] = "Jingkong Cang"     #有相应的key时为修改,没有为增加
print(info_dic)

 

③ 删除

#3种删除方式
info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
info_dic.pop('stu1101')            #pop删除,指定删除的key
print(info_dic)
#{'stu1103': 'XiaoZe Maliya', 'stu1102': 'LongZe Luola'}
del info_dic['stu1102']           #del删除,指定删除的key
print(info_dic)
#{'stu1103': 'XiaoZe Maliya'}
info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
info_dic.popitem()               #随机删除,没卵用
print(info_dic)
#{'stu1101': 'TengLan Wu', 'stu1103': 'XiaoZe Maliya'}

 

④ 查找value值

info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
print(info_dic.get('stu1102'))   #get查找,通过key查找value值
#LongZe Luola
print(info_dic['stu1102'])     #通过key直接查找,但是如果输入查找的key不存在的话,就会报错,get则不会
#LongZe Luola

 

⑤ 字典多级嵌套

  "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"])
#['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']

⑥ 循环

info_dic = {'stu1101': "TengLan Wu",'stu1102': "LongZe Luola",'stu1103': "XiaoZe Maliya",}
for stu_nu in info_dic:
  print(stu_nu,info_dic[stu_nu])    #循环默认提取的是key
#stu1103 XiaoZe Maliya
#stu1101 TengLan Wu
#stu1102 LongZe Luola
for k,v in info_dic.items():       #先把dict生成list,数据量大的时候费时,不建议使用
  print(k,v)
#stu1103 XiaoZe Maliya
#stu1101 TengLan Wu
#stu1102 LongZe Luola

八、集合
如:{'solo', 33, 'alex', 22, 'eric', 'wupeiqi', 11}
注:集合是一个无序的,不重复的数据组合。去重性,把一个列表变成集合,就自动去重了。关系测试,测试两组数据之前的交集、差集、并集
1、创建集合

 

#标准创建方式
info_set = set(["alex","wupeiqi","eric","solo",11,22,33])
print(info_set,type(info_set))
#{33, 11, 'wupeiqi', 'solo', 'alex', 'eric', 22} <class 'set'>

2、集合类常用功能
① 添加

#添加的两种方式
set_1 = set(["alex","wupeiqi","eric","solo"])
set_1.add(11)             #add只能添加一个元素
print(set_1)
#{'alex', 'solo', 'eric', 11, 'wupeiqi'}
set_1 = set(["alex","wupeiqi","eric","solo"])
set_1.update([11,22,33])
print(set_1)              #update可以添加多个元素
#{33, 11, 'alex', 'wupeiqi', 'eric', 22, 'solo'}

② 删除

#删除的三种方式
set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_1.remove("alex")          #remove 删除指定元素
print(set_1)
#{'eric', 33, 'solo', 11, 22, 'wupeiqi'}
set_1.pop()               #pop 随机删除元素
print(set_1)
#{33, 'wupeiqi', 11, 22, 'solo'}
set_1.discard("solo")          #discard 删除指定元素,与remove区别在于,如果元素不存在也不会报错
set_1.discard(55)
print(set_1)
#{33, 'wupeiqi', 11, 22}

3、集合关系测试
① 交集

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
print(set_1.intersection(set_2))      #intersection 取两个set的交集 set_1和set_2可以互换位置
#{33, 11, 22}

② 并集

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
print(set_1.union(set_2))           #union 取两个set集合的并集 set_1和set_2可以互换位置
#{33, 66, 11, 44, 'eric', 55, 'solo', 22, 'wupeiqi', 'alex'}

③ 差集

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
print(set_1.difference(set_2))         #difference 取两个set集合的差集 set_1有但是set_2没有的集合
#{'solo', 'eric', 'wupeiqi', 'alex'}

④ 子集、父集

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
set_3 = set([11,22,33])
print(set_1.issubset(set_2))           #issubset 子集
#False
print(set_1.issuperset(set_3))          #issuperset 父集
#True

⑤ 对称差集

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
print(set_1.symmetric_difference(set_2))      #symmetric_difference 对称差集=两个集合并集减去合集
#{66, 'solo', 'eric', 'alex', 55, 'wupeiqi', 44}

⑥ 运算符做关系测试

set_1 = set(["alex","wupeiqi","eric","solo",11,22,33])
set_2 = set([11,22,33,44,55,66])
set_union = set_1 | set_2      # 并集
set_intersection = set_1 & set_2  # 交集
set_difference = set_1 - set_2   # 差集
set_symmetric_difference = set_1 ^ set_2 # 对称差集

六、模块初识

Python有大量的模块,从而使得开发Python程序非常简洁。类库有包括三中:
① 、Python内部提供的模块
②、业内开源的模块
③、程序员自己开发的模块:Python脚本的名字不要与模块名相同

1、sys模块(系统内置)
① sys.argv 用来捕获执行python脚本时传入的参数
② sys.stdin 标准信息输入
③ sys.stdout 标准定向输出
④ sys.stdout.flush 强制刷新标准输出缓存

import time
import sys
for i in range(5):
  print(i),
  sys.stdout.flush()
  time.sleep(1)
# 这样设计是为了打印一个数每秒五秒钟,但如果您运行它,因为它是现在(取决于您的默认系统缓冲),
# 你可能看不到任何输出 CodeGo.net,直到再一次全部,你会看到0 1 2 3 4打印到屏幕上。
# 这是输出被缓冲,除非你sys.stdout之后每print你不会看到从输出中取出sys.stdout.flush()网上看到的差别

2、os模块(与系统进行交互)
① os.dir、os.popen调用当前系统命令

3、platform模块(识别当前运行的系统)

七、运算符
1、算数运算:

2、比较运算:

3、赋值运算:

4、逻辑运算:

5、成员运算:

6、身份运算:

7、位运算:

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