Python|十进制 ln() 方法

Decimal#ln() : ln()是一个 Decimal 类方法，它返回 Decimal 值的自然（以 e 为底）对数。

Syntax: Decimal.ln()

Parameter: Decimal values

Return: the natural (base e) logarithm of the Decimal value.

代码 #1：ln() 方法的示例

# Python Program explaining 
# ln() method
  
# loading decimal library
from decimal import *
  
  
# Initializing a decimal value
a = Decimal('.9932')
  
b = Decimal('0.142857')
  
# printing Decimal values
print ("Decimal value a : ", a)
print ("Decimal value b : ", b)
  
  
# Using Decimal.ln() method
print ("\n\nDecimal a with ln() method : ", a.ln())
  
print ("Decimal b with ln() method : ", b.ln())

输出 ：

Decimal value a :  0.9932
Decimal value b :  0.142857


Decimal a with ln() method :  -0.006823225348125508334064182053
Decimal b with ln() method :  -1.945911149055813305438686327

代码 #2：ln() 方法的示例

# Python Program explaining 
# ln() method
  
# loading decimal library
from decimal import *
  
  
# Initializing a decimal value
a = Decimal('3.14')
  
b = Decimal('321e + 5')
  
# printing Decimal values
print ("Decimal value a : ", a)
print ("Decimal value b : ", b)
  
  
# Using Decimal.ln() method
print ("\n\nDecimal a with ln() method : ", a.ln())
  
print ("Decimal b with ln() method : ", b.ln())

输出 ：

Decimal value a :  3.14
Decimal value b :  3.21E+7


Decimal a with ln() method :  1.144222799920161998805694448
Decimal b with ln() method :  17.28436658810024428478960133