Python数学模块

在程序开发的时候，可能不仅仅需要加减乘除这样的简单运算，还需要乘方、开方、取绝对值等等这样的复杂运算。这一篇文章将要介绍Python的数学内置模块math，这个内置模块能够解决常见的绝大部分数学运算。

常用的math方法

math.e

自然常数e

math.pi

圆周率pi

math.exp(x)

返回e的x次方

math.expm1(x)

返回e的x次方减1

math.log(x[, base])

返回x的以base为底的对数，base默认为e

math.log10(x)

返回x的以10为底的对数 相当于 math.log(x，10)

math.pow(x, y)

返回x的y次方

math.sqrt(x)

返回x的平方根

math.ceil(x)

返回不小于x的整数

math.floor(x)

返回不大于x的整数

math.trunc(x)

返回x的整数部分

math.modf(x)

返回x的小数和整数 元组形式

math.fabs(x)

返回x的绝对值

math.fmod(x, y)

返回x%y(取余)

math.fsum([x, y, ...])

返回无损精度的和

math.factorial(x)

返回x的阶乘 阶乘就是 1*2*3...*(x-2)*(x-1)*x

math.isinf(x)

若x为无穷大，返回True；否则，返回False

math.isnan(x)

若x不是数字，返回True；否则，返回False

math.hypot(x, y)

返回以x和y为直角边的斜边长

math.copysign(x, y)

若y<0，返回-1乘以x的绝对值； 否则，返回x的绝对值

math.frexp(x)

返回m和i，满足m乘以2的i次方

math.ldexp(m, i)

返回m乘以2的i次方

math.sin(x)

返回x(弧度)的三角正弦值

math.asin(x)

返回x的反三角正弦值

math.cos(x)

返回x(弧度)的三角余弦值

math.acos(x)

返回x的反三角余弦值

math.tan(x)

返回x(弧度)的三角正切值

math.atan(x)

返回x的反三角正切值

math.atan2(x, y)

返回x/y的反三角正切值

math.sinh(x)

返回x的双曲正弦函数

math.asinh(x)

返回x的反双曲正弦函数

math.cosh(x)

返回x的双曲余弦函数

math.acosh(x)

返回x的反双曲余弦函数

math.tanh(x)

返回x的双曲正切函数

math.atanh(x)

返回x的反双曲正切函数

math.erf(x)

返回x的误差函数

math.erfc(x)

返回x的余误差函数

math.gamma(x)

返回x的伽玛函数

math.lgamma(x)

返回x的绝对值的自然对数的伽玛函数

打印了部分例子

>>> import math>>> >>> math.e2.718281828459045>>> math.pi3.141592653589793>>> math.exp(3)20.085536923187668>>> math.expm1(3)19.085536923187668>>> math.expm1(4)53.598150033144236>>> math.log(math.e)1.0>>> math.pow(3,2)9.0>>> math.pow(2,3)8.0>>> math.sqrt(8)2.8284271247461903>>> math.sqrt(9)3.0>>> math.ceil(5.1)6>>> math.ceil(5)5>>> math.ceil(5.0)5>>> math.floor(5.1)5>>> math.floor(5.9)5>>> math.trunc(5.1)5>>> math.trunc(7.1)7>>> math.modf(7.1)(0.09999999999999964, 7.0)>>> >>> math.fabs(10)10.0>>> math.fabs(-10)10.0>>> math.factorial(5)120>>> math.factorial(6)720>>> 

math模块下其他方法

>>> help(math)Help on built-in module math:NAME mathDESCRIPTION This module is always available. It provides access to the mathematical functions defined by the C standard.FUNCTIONS acos(x, /) Return the arc cosine (measured in radians) of x.  acosh(x, /) Return the inverse hyperbolic cosine of x.  asin(x, /) Return the arc sine (measured in radians) of x.  asinh(x, /) Return the inverse hyperbolic sine of x.  atan(x, /) Return the arc tangent (measured in radians) of x.  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(x, /) Return the inverse hyperbolic tangent of x.  ceil(x, /) Return the ceiling of x as an Integral.  This is the smallest integer >= x.  copysign(x, y, /) Return a float with the magnitude (absolute value) of x but the sign of y.  On platforms that support signed zeros, copysign(1.0, -0.0) returns -1.0.  cos(x, /) Return the cosine of x (measured in radians).  cosh(x, /) Return the hyperbolic cosine of x.  degrees(x, /) Convert angle x from radians to degrees.  erf(x, /) Error function at x.  erfc(x, /) Complementary error function at x.  exp(x, /) Return e raised to the power of x.  expm1(x, /) Return exp(x)-1.  This function avoids the loss of precision involved in the direct evaluation of exp(x)-1 for small x.  fabs(x, /) Return the absolute value of the float x.  factorial(x, /) Find x!.  Raise a ValueError if x is negative or non-integral.  floor(x, /) Return the floor of x as an Integral.  This is the largest integer <= x.  fmod(x, y, /) Return fmod(x, y), according to platform C.  x % y may differ.  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(seq, /) Return an accurate floating point sum of values in the iterable seq.  Assumes IEEE-754 floating point arithmetic.  gamma(x, /) Gamma function at x.  gcd(x, y, /) greatest common divisor of x and y  hypot(x, y, /) Return the Euclidean distance, sqrt(x*x + y*y).  isclose(a, b, *, rel_tol=1e-09, abs_tol=0.0) Determine whether two floating point numbers are close in value.  rel_tol maximum difference for being considered "close