Python | frexp() Function

frexp() function is one of the Standard math Library function in Python.

It returns mantissa and exponent as a pair (m, e) of a given value x, where mantissa m is a floating point number and e exponent is an integer value. m is a float and e is an integer such that x == m * 2**e exactly.

If x is zero, returns (0.0, 0), otherwise 0.5 <= abs(m) < 1. This is used to “pick apart” the internal representation of a float in a portable way.

Syntax: math.frexp( x )

Parameters: Any valid number (positive or negative).

Returns: Returns mantissa and exponent as a pair (m, e) value of a given number x.

Exception: If x is not a number, function will return TypeError.

Code #1:

# Python3 code demonstrate frexp() function

# importing math library
import math


# calculating mantissa and
# exponent of given integer
print(math.frexp(3))
print(math.frexp(15.7))
print(math.frexp(-15))

Output:

(0.75, 2)
(0.98125, 4)
(-0.9375, 4)

Code #2:

# Python3 code demonstrate frexp() function

# importing math library
import math

# creating a list
lst = [15, 13.76, 17.5, 21]

# creating a tuple
tpl = (-15.85, -41.24, -11.2, 54)

# calculating mantissa and exponent
# of 1st, 3rd elements in list
print(math.frexp(lst[0]))
print(math.frexp(lst[2]))

# calculating mantissa and exponent
# of 2nd, 3rd and 4th elements in tuple
print(math.frexp(tpl[1]))
print(math.frexp(tpl[2]))
print(math.frexp(tpl[3]))

Output:

(0.9375, 4)
(0.546875, 5)
(-0.644375, 6)
(-0.7, 4)
(0.84375, 6)

Code #3: If the x parameter is not a number, frexp() function will return a TypeError.

# Python3 code demonstrates when error occurs
import math

print(math.frexp('25'))

Output:

TypeError: a float is required