Python中的小数函数 |设置 1

Python在其定义中提供了某些方法来使用模块“decimal”执行更快的十进制浮点运算。
小数的重要运算
1. sqrt() :- 这个函数计算十进制数的平方根。
2. exp() :- 此函数返回十进制数的e^x（指数） 。

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)

输出：

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

3. ln() :- 该函数用于计算十进制数的自然对数。
4. log10() :- 此函数用于计算十进制数的log(base 10) 。

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)

输出：

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

5. as_tuple() :- 将十进制数作为包含3 个参数的元组返回，符号（0 表示 +，1 表示 -）、数字和指数值。
6. fma(a,b) :- 这个“fma”代表融合乘法和加法。它根据参数中的数字计算(num*a)+b 。此函数中不发生 (num*a) 的舍入。
例子 ：

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)

输出：

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() :- 此函数用于比较十进制数。如果第一个 Decimal 参数大于第二个，则返回 1，如果第一个 Decimal 参数小于第二个，则返回 -1，如果两者相等，则返回 0。
8. compare_total_mag() :- 比较十进制数的总大小。如果第一个 Decimal 参数大于第二个（忽略符号），则返回 1，如果第一个 Decimal 参数小于第二个（忽略符号），则返回 -1，如果两者相等（忽略符号），则返回 0。

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))

输出：

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

9. copy_abs() :- 这个函数打印十进制参数的绝对值。
10. copy_negate() :- 这个函数打印十进制参数的否定。
11. copy_sign() :- 该函数通过从第二个参数复制符号来打印第一个参数。

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))

输出：

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() :- 该函数计算两个十进制数的最大值。
13. min() :- 该函数计算两个十进制数的最小值。

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))

输出：

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