Decimal Functions in Python | Set 1

Python in its definition provides certain methods to perform faster decimal floating point arithmetic using the module “decimal”. 
Important operations on Decimals
1. sqrt() :- This function computes the square root of the decimal number.
2. exp() :- This function returns the e^x (exponent) of the decimal number.

Python3

# Python code to demonstrate the working of
# sqrt() and exp()

# importing "decimal" module to use decimal functions
import decimal

# using exp() to compute the exponent of decimal number
a = decimal.Decimal(4.5).exp()

# using sqrt() to compute the square root of decimal number
b = decimal.Decimal(4.5).sqrt()

# printing the exponent
print ("The exponent of decimal number is : ",end="")
print (a)

# printing the square root
print ("The square root of decimal number is : ",end="")
print (b)

Output: 

The exponent of decimal number is : 90.01713130052181355011545675
The square root of decimal number is : 2.121320343559642573202533086

3. ln() :- This function is used to compute natural logarithm of the decimal number.
4. log10() :- This function is used to compute log(base 10) of a decimal number.

Python3

# Python code to demonstrate the working of
# ln() and log10()

# importing "decimal" module to use decimal functions
import decimal

# using ln() to compute the natural log of decimal number
a = decimal.Decimal(4.5).ln()

# using sqrt() to compute the log10 of decimal number
b = decimal.Decimal(4.5).log10()

# printing the natural logarithm
print ("The natural logarithm of decimal number is : ",end="")
print (a)

# printing the log10
print ("The log(base 10) of decimal number is : ",end="")
print (b)

Output: 

The natural logarithm of decimal number is : 1.504077396776274073373258352
The log(base 10) of decimal number is : 0.6532125137753436793763169118

5. as_tuple() :- Returns the decimal number as tuple containing 3 arguments, sign(0 for +, 1 for -), digits and exponent value.
6. fma(a,b) :- This “fma” stands for fused multiply and add. It computes (num*a)+b from the numbers in argument. No rounding of (num*a) takes place in this function.
Example :

decimal.Decimal(5).fma(2,3) --> (5*2)+3 = 13

Python3

# Python code to demonstrate the working of
# as_tuple() and fma()

# importing "decimal" module to use decimal functions
import decimal

# using as_tuple() to return decimal number as tuple
a = decimal.Decimal(-4.5).as_tuple()

# using fma() to compute fused multiply and addition
b = decimal.Decimal(5).fma(2,3)

# printing the tuple
print ("The tuple form of decimal number is : ",end="")
print (a)

# printing the fused multiple and addition
print ("The fused multiply and addition of decimal number is : ",end="")
print (b)

Output: 

The tuple form of decimal number is : DecimalTuple(sign=1, digits=(4, 5), exponent=-1)
The fused multiply and addition of decimal number is : 13

7. compare() :- This function is used to compare decimal numbers. Returns 1 if 1st Decimal argument is greater than 2nd, -1 if 1st Decimal argument is smaller than 2nd and 0 if both are equal.
8. compare_total_mag() :- Compares the total magnitude of decimal numbers. Returns 1 if 1st Decimal argument is greater than 2nd(ignoring sign), -1 if 1st Decimal argument is smaller than 2nd(ignoring sign) and 0 if both are equal(ignoring sign).

Python3

# Python code to demonstrate the working of
# compare() and compare_total_mag()

# importing "decimal" module to use decimal functions
import decimal

# Initializing decimal number
a = decimal.Decimal(9.53)

# Initializing decimal number
b = decimal.Decimal(-9.56)

# comparing decimal numbers using compare()
print ("The result of comparison using compare() is : ",end="")
print (a.compare(b))

# comparing decimal numbers using compare_total_mag()
print ("The result of comparison using compare_total_mag() is : ",end="")
print (a.compare_total_mag(b))

Output: 

The result of comparison using compare() is : 1
The result of comparison using compare_total_mag() is : -1

9. copy_abs() :- This function prints the absolute value of decimal argument.
10. copy_negate() :- This function prints the negation of decimal argument.
11. copy_sign() :- This function prints the first argument by copying the sign from 2nd argument.

Python3

# Python code to demonstrate the working of
# copy_abs(),copy_sign() and copy_negate()

# importing "decimal" module to use decimal functions
import decimal

# Initializing decimal number
a = decimal.Decimal(9.53)

# Initializing decimal number
b = decimal.Decimal(-9.56)

# printing absolute value using copy_abs()
print ("The absolute value using copy_abs() is : ",end="")
print (b.copy_abs())

# printing negated value using copy_negate()
print ("The negated value using copy_negate() is : ",end="")
print (b.copy_negate())

# printing sign effected value using copy_sign()
print ("The sign effected value using copy_sign() is : ",end="")
print (a.copy_sign(b))

Output: 

The absolute value using copy_abs() is : 9.5600000000000004973799150320701301097869873046875
The negated value using copy_negate() is : 9.5600000000000004973799150320701301097869873046875
The sign effected value using copy_sign() is : -9.5299999999999993605115378159098327159881591796875

12. max() :- This function computes the maximum of two decimal numbers.
13. min() :- This function computes the minimum of two decimal numbers.

Python3

# Python code to demonstrate the working of
# min() and max()

# importing "decimal" module to use decimal functions
import decimal

# Initializing decimal number
a = decimal.Decimal(9.53)

# Initializing decimal number
b = decimal.Decimal(7.43)

# printing minimum of both values
print ("The minimum of two numbers is : ",end="")
print (a.min(b))

# printing maximum of both values
print ("The maximum of two numbers is : ",end="")
print (a.max(b))

Output: 

The minimum of two numbers is : 7.429999999999999715782905696
The maximum of two numbers is : 9.529999999999999360511537816