[python] How can I convert radians to degrees with Python?

In the math module, I could only find math.cos(x), with cos/sin/tan/acos/asin/atan. This returns the answer in radians. How can I get the answer in degrees?

Here's my code:

import math

x = math.cos(1)
y = x * 180 / math.pi
print(y)
30.9570417874

My calculator, on deg, gives me:

cos(1)
0.9998476...

-fix- because you want to change from radians to degrees, it is actually rad=deg * math.pi /180 and not deg*180/math.pi

import math
x=1                # in deg
x = x*math.pi/180  # convert to rad
y = math.cos(x)    # calculate in rad

print y

in 1 line it can be like this

y=math.cos(1*math.pi/180)

I also like to define my own functions that take and return arguments in degrees rather than radians. I am sure there some capitalization purest who don't like my names, but I just use a capital first letter for my custom functions. The definitions and testing code are below.

#Definitions for trig functions using degrees.
def Cos(a):
    return cos(radians(a))
def Sin(a):
    return sin(radians(a))
def Tan(a):
    return tan(radians(a))
def ArcTan(a):
    return degrees(arctan(a))
def ArcSin(a):
    return degrees(arcsin(a))
def ArcCos(a):
    return degrees(arccos(a))

#Testing Code
print(Cos(90))
print(Sin(90))
print(Tan(45))
print(ArcTan(1))
print(ArcSin(1))
print(ArcCos(0))

Note that I have imported math (or numpy) into the namespace with

from math import *

Also note, that my functions are in the namespace in which they were defined. For instance,

math.Cos(45)

does not exist.

radian can also be converted to degree by using numpy

print(np.rad2deg(1))
57.29577951308232

if needed to roundoff ( I did with 6 digits after decimal below), then

print(np.round(np.rad2deg(1), 6)

57.29578

You can simply convert your radian result to degree by using

math.degrees and rounding appropriately to the required decimal places

for example

>>> round(math.degrees(math.asin(0.5)),2)
30.0
>>> 

Python convert radians to degrees or degrees to radians:

What are Radians and what problem does it solve?:

Radians and degrees are two separate units of measure that help people express and communicate precise changes in direction. Wikipedia has some great intuition with their infographics on how one Radian is defined relative to degrees:

https://en.wikipedia.org/wiki/Radian

Python examples using libraries calculating degrees from radians:

>>> import math
>>> math.degrees(0)                       #0 radians == 0 degrees
0.0
>>> math.degrees(math.pi/2)               #pi/2 radians is 90 degrees
90.0
>>> math.degrees(math.pi)                 #pi radians is 180 degrees
180.0      
>>> math.degrees(math.pi+(math.pi/2))     #pi+pi/2 radians is 270 degrees
270.0 
>>> math.degrees(math.pi+math.pi)         #2*pi radians is 360 degrees
360.0      

Python examples using libraries calculating radians from degrees:

>>> import math
>>> math.radians(0)           #0 degrees == 0 radians
0.0
>>> math.radians(90)          #90 degrees is pi/2 radians
1.5707963267948966
>>> math.radians(180)         #180 degrees is pi radians
3.141592653589793
>>> math.radians(270)         #270 degrees is pi+(pi/2) radians
4.71238898038469
>>> math.radians(360)         #360 degrees is 2*pi radians
6.283185307179586

Source: https://docs.python.org/3/library/math.html#angular-conversion

The mathematical notation:

You can do degree/radian conversion without libraries:

If you roll your own degree/radian converter, you have to write your own code to handle edge cases.

Mistakes here are easy to make, and will hurt just like it hurt the developers of the 1999 mars orbiter who sunk $125m dollars crashing it into Mars because of non intuitive edge cases here.

Lets crash that orbiter and Roll our own Radians to Degrees:

Invalid radians as input return garbage output.

>>> 0 * 180.0 / math.pi                         #0 radians is 0 degrees
0.0
>>> (math.pi/2) * 180.0 / math.pi               #pi/2 radians is 90 degrees
90.0
>>> (math.pi) * 180.0 / math.pi                 #pi radians is 180 degrees
180.0
>>> (math.pi+(math.pi/2)) * 180.0 / math.pi     #pi+(pi/2) radians is 270 degrees
270.0
>>> (2 * math.pi) * 180.0 / math.pi             #2*pi radians is 360 degrees
360.0

Degrees to radians:

>>> 0 * math.pi / 180.0              #0 degrees in radians
0.0
>>> 90 * math.pi / 180.0             #90 degrees in radians
1.5707963267948966
>>> 180 * math.pi / 180.0            #180 degrees in radians
3.141592653589793
>>> 270 * math.pi / 180.0            #270 degrees in radians
4.71238898038469
>>> 360 * math.pi / 180.0            #360 degrees in radians
6.283185307179586

Expressing multiple rotations with degrees and radians

Single rotation valid radian values are between 0 and 2*pi. Single rotation degree values are between 0 and 360. However if you want to express multiple rotations, valid radian and degree values are between 0 and infinity.

>>> import math
>>> math.radians(360)                 #one complete rotation
6.283185307179586
>>> math.radians(360+360)             #two rotations
12.566370614359172
>>> math.degrees(12.566370614359172)  #math.degrees and math.radians preserve the
720.0                                 #number of rotations

Collapsing multiple rotations:

You can collapse multiple degree/radian rotations into a single rotation by modding against the value of one rotation. For degrees you mod by 360, for radians you modulus by 2*pi.

>>> import math
>>> math.radians(720+90)        #2 whole rotations plus 90 is 14.14 radians
14.137166941154069
>>> math.radians((720+90)%360)  #14.1 radians brings you to 
1.5707963267948966              #the end point as 1.57 radians.

>>> math.degrees((2*math.pi)+(math.pi/2))            #one rotation plus a quarter 
450.0                                                #rotation is 450 degrees.
>>> math.degrees(((2*math.pi)+(math.pi/2))%(2*math.pi)) #one rotation plus a quarter
90.0                                                    #rotation brings you to 90.

Protip

Khan academy has some excellent content to solidify intuition around trigonometry and angular mathematics: https://www.khanacademy.org/math/algebra2/trig-functions/intro-to-radians-alg2/v/introduction-to-radians

I like this method,use sind(x) or cosd(x)

import math

def sind(x):
    return math.sin(math.radians(x))

def cosd(x):
    return math.cos(math.radians(x))