Decimal＃copy_sign()：copy_sign()是一个Decimal类方法，它返回第一个Decimal值的副本，其符号设置为与第二个Decimal值的符号相同。
用法：
Decimal.copy_sign()
参数：
Decimal values
返回：
the copy of the first Decimal value with the sign set
to be the same as the sign of the second Decimal value.
代码＃1：copy_sign()方法示例
# Python Program explaining
# copy_sign() method
# loading decimal library
from decimal import *
# Initializing a decimal value
a = Decimal(-1)
b = Decimal('0.142857')
# printing Decimal values
print ("Decimal value a:", a)
print ("Decimal value b:", b)
# Using Decimal.copy_sign() method
print ("\n\nDecimal a with copy_sign() method:", a.copy_sign(a))
print ("Decimal a with copy_sign() method:", a.copy_sign(b))
print ("Decimal b with copy_sign() method:", b.copy_sign(a))
输出：
Decimal value a: -1
Decimal value b: 0.142857
Decimal a with copy_sign() method: -1
Decimal a with copy_sign() method: 1
Decimal b with copy_sign() method: -0.142857
代码2：copy_sign()方法示例
# Python Program explaining
# copy_sign() 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.copy_sign() method
print ("\n\nDecimal a with copy_sign() method:", a.copy_sign(a))
print ("Decimal a with copy_sign() method:", a.copy_sign(b))
print ("Decimal b with copy_sign() method:", b.copy_sign(a))
输出：
Decimal value a: -3.14
Decimal value b: 3.21E+7
Decimal a with copy_sign() method: -3.14
Decimal a with copy_sign() method: 3.14
Decimal b with copy_sign() method: -3.21E+7
