python导入math_python之math模块

1.math简介

>>>import math #导入math模块

>>>dir(math) #这句可查看所有函数名列表

>>>help(math) #查看具体定义及函数原型

2.常用函数

acos(x) # Return the arc cosine (measured in radians) of x.

asin(x) # Return the arc sine (measured in radians) 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.

ceil(x) # Return the ceiling of x as a float.

# This is the smallest integral value >= x.

cos(x) # Return the cosine of x (measured in radians).

cosh(x) # Return the hyperbolic(双曲线的) cosine of x.

degrees(x) # converts angle x from radians(弧度) to degrees

exp(x) # Return e raised to the power of x.

fabs(x) # Return the absolute value of the float x.

floor(x) # Return the floor of x as a float.

# This is the largest integral value <= 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.

hypot(x,y) # Return the Euclidean distance, sqrt(x*x + y*y).

ldexp(x, i) # x * (2**i)

log(x[, base]) # the logarithm of x to the given base.

# If the base not specified, returns the natural logarithm (base e) of x.

log10(x) # the base 10 logarithm of x.

modf(x) # Return the fractional and integer parts of x. Both results carry the sign

# of x. The integer part is returned as a real.

pow(x,y) # Return x**y (x to the power of y).

radians(x) # converts angle x from degrees to radians

sin(x) # Return the sine of x (measured in radians).

sinh(x) # Return the hyperbolic sine of x.

sqrt(x) # Return the square root of x.

tan(x) # Return the tangent of x (measured in radians).

tanh(x) # Return the hyperbolic tangent of x.

另外该模块定义了两个常量:

e = 2.7182818284590451

pi = 3.1415926535897931