Converting a number from octal binary and hexadecimal system to decimal number system.

n1 = 0o17 # representation of octal numbers

n2 = 0b1110010 # representation of binary numbers

n3 = 0x1c2 # representation of hexadecimal number

We can do this with the help of int() method like int(n1), int(n2), int(n3).

# representation of octal numbers
n1 = 0o17
# representation of binary numbers
n2 = 0b1110010
# representation of hexadecimal number
n3 = 0x1c2
print("Octal to Decimal : ", int(n1))
print("Binary to Decimal : ", int(n2))
print("Hex to Decimal : ", int(n3))

Converting a decimal integer to octal, binary and hexadecimal system.

bin() : For decimal to binary conversion.

oct() : For decimal to octal conversion.

hex() : For decimal to hexadecimal conversion

num = 10
print("10 in octal form : ", oct(num))
print("10 in hexadecimal form : ", hex(num))
print("10 in binary form : ", bin(num))

You can remove the first two character (0o, 0x, 0b) for each form to get the formatted result. Let us modify the above code to achieve this.

Note : We just did some casting here, we’ll learn this in upcoming lessons.

num = 10
print("10 in octal form : ", str(oct(num)).replace('0o', ''))
print("10 in hexadecimal form : ", str(hex(num)).replace('0x', ''))
print("10 in binary form : ", str(bin(num)).replace('0b', ''))

Cool Mathematical methods

ceil(x) : It raises x value to the next higher integer value. For example, ceil(4.5) gives 5.

floor(x) : It decreases x value to previous integer value. For example, floor(4.5) gives 4.

degrees(x) : It converts angle value x from radians to degrees.

radians(x) : It converts x value from degree to radians.

sin(x) : It gives a sine value of x.

cos(x) : It gives a cosine value of x.

tan(x) : It gives a tan value of x.

exp(x) : It gives exponential of x.

fabs(x) : It gives absolute value of x. Like fabs(-4.53) gives 4.53.

factorial(x) : It gives the factorial of x.

fmod(x,y) : It gives remainder of division of x & y. Like, fmod(13.5,3) gives 1.5.

fsum(val) : It gives the accurate sum of floating point values.

log10(x) : It gives base-10 logarithm of x.

sqrt(x) : It gives the square-root of number x.

pow(x,y) : It raises x value to the power y.

pow(x,y,z) : It raises x value to the power y mod z.

gcd(x,y) : It is used to find the greatest common divisor of x & y.

trunc(x) : It returns real value of x is truncated to integer value. Like trunc(43.545) returns 43.

isnan(x) : It returns True if x is not a number.

eval(expression) : It returns evaluated arithmetic expression. Like, eval(3*7) gives 21.

# Illustration of mathematical methods :

# We need to import python in-built module 'math' to access mathematical methods

import math as m # creating 'm' as alias(nickname) for 'math'

print("ceil(4.5) : ", m.ceil(4.5))
print("floor(4.5) : ", m.floor(4.5))
print("degrees(180/3.14) : ", m.degrees(180/3.14))
print("radians(90) : ", m.radians(90))
print("sin(30) : ", m.sin(30))
print("cos(45) : ", m.cos(45))
print("tan(60) : ", m.tan(60))
print("exp(2) : ", m.exp(2))
print("fabs(-2.86) : ", m.fabs(-2.86))
print("factorial(6) : ", m.factorial(6))
print("fmod(17,2) : ", m.fmod(17,2))
print("log10(2) : ", m.log10(2))
print("sqrt(20) : ", m.sqrt(20))
print("pow(2,5) : ", m.pow(2,5))
print("gcd(50,100) : ", m.gcd(50,100))
print("trunc(7.677) : ", m.trunc(7.677))
print("isnan(2) : ", m.isnan(2))
print("eval('(2*3)+(9/3)') : ", eval("(2*3)+(9/3)"))

That’s all, see you in the next lecture.