python math库

[lucky-lucky]

在python中使用import math就可以使用math库的所有内容了
但是这个math库为什么在python的安装目录中找不见？
其它的一些库，比如decimal，这些库都可以在系统目录下找的见的啊，求解

[socrates]

自带的，好像是看不到。

>>> reload(pyHook)
<module 'pyHook' from 'C:\Python26\lib\site-packages\pyHook\__init__.pyc'>
>>> import math
>>> reload(math)
<module 'math' (built-in)>

不知道你看这想做什么，如果是看接口的话，可使用help命令，如下：

>>> help(math)
Help on built-in module math:

NAME
    math

FILE
    (built-in)

DESCRIPTION
    This module is always available.  It provides access to the
    mathematical functions defined by the C standard.

FUNCTIONS
    acos(...)
        acos(x)
        
        Return the arc cosine (measured in radians) of x.
    
    acosh(...)
        acosh(x)
        
        Return the hyperbolic arc cosine (measured in radians) of x.
    
    asin(...)
        asin(x)
        
        Return the arc sine (measured in radians) of x.
    
    asinh(...)
        asinh(x)
        
        Return the hyperbolic arc sine (measured in radians) of x.
    
    atan(...)
        atan(x)
        
        Return the arc tangent (measured in radians) of x.
    
    atan2(...)
        atan2(y, x)
        
        Return the arc tangent (measured in radians) of y/x.
        Unlike atan(y/x), the signs of both x and y are considered.
    
    atanh(...)
        atanh(x)
        
        Return the hyperbolic arc tangent (measured in radians) of x.
    
    ceil(...)
        ceil(x)
        
        Return the ceiling of x as a float.
        This is the smallest integral value >= x.
    
    copysign(...)
        copysign(x, y)
        
        Return x with the sign of y.
    
    cos(...)
        cos(x)
        
        Return the cosine of x (measured in radians).
    
    cosh(...)
        cosh(x)
        
        Return the hyperbolic cosine of x.
    
    degrees(...)
        degrees(x)
        
        Convert angle x from radians to degrees.
    
    exp(...)
        exp(x)
        
        Return e raised to the power of x.
    
    fabs(...)
        fabs(x)
        
        Return the absolute value of the float x.
    
    factorial(...)
        factorial(x) -> Integral
        
        Find x!. Raise a ValueError if x is negative or non-integral.
    
    floor(...)
        floor(x)
        
        Return the floor of x as a float.
        This is the largest integral value <= x.
    
    fmod(...)
        fmod(x, y)
        
        Return fmod(x, y), according to platform C.  x % y may differ.
    
    frexp(...)
        frexp(x)
        
        Return the mantissa and exponent of x, as pair (m, e).
        m is a float and e is an int, such that x = m * 2.**e.
        If x is 0, m and e are both 0.  Else 0.5 <= abs(m) < 1.0.
    
    fsum(...)
        fsum(iterable)
        
        Return an accurate floating point sum of values in the iterable.
        Assumes IEEE-754 floating point arithmetic.
    
    hypot(...)
        hypot(x, y)
        
        Return the Euclidean distance, sqrt(x*x + y*y).
    
    isinf(...)
        isinf(x) -> bool
        
        Check if float x is infinite (positive or negative).
    
    isnan(...)
        isnan(x) -> bool
        
        Check if float x is not a number (NaN).
    
    ldexp(...)
        ldexp(x, i)
        
        Return x * (2**i).
    
    log(...)
        log(x[, base])
        
        Return the logarithm of x to the given base.
        If the base not specified, returns the natural logarithm (base e) of x.
    
    log10(...)
        log10(x)
        
        Return the base 10 logarithm of x.
    
    log1p(...)
        log1p(x)
        
        Return the natural logarithm of 1+x (base e).
        The result is computed in a way which is accurate for x near zero.
    
    modf(...)
        modf(x)
        
        Return the fractional and integer parts of x.  Both results carry the sign
        of x and are floats.
    
    pow(...)
        pow(x, y)
        
        Return x**y (x to the power of y).
    
    radians(...)
        radians(x)
        
        Convert angle x from degrees to radians.
    
    sin(...)
        sin(x)
        
        Return the sine of x (measured in radians).
    
    sinh(...)
        sinh(x)
        
        Return the hyperbolic sine of x.
    
    sqrt(...)
        sqrt(x)
        
        Return the square root of x.
    
    tan(...)
        tan(x)
        
        Return the tangent of x (measured in radians).
    
    tanh(...)
        tanh(x)
        
        Return the hyperbolic tangent of x.
    
    trunc(...)
        trunc(x:Real) -> Integral
        
        Truncates x to the nearest Integral toward 0. Uses the __trunc__ magic method.

DATA
    e = 2.7182818284590451
    pi = 3.1415926535897931


>>> 

[lucky-lucky]

哦哦，明白鸟，十分感谢