Python| math.factorial()函数

在Python中，数学模块包含许多数学运算，可以使用该模块轻松执行。 math.factorial()函数返回所需数字的阶乘。

Syntax: math.factorial(x)

Parameter:
x: This is a numeric expression.

Returns:  factorial of desired number.

代码#1：

# Python code to demonstrate the working of factorial()
    
# importing "math" for mathematical operations 
import math 
    
x = 5
    
# returning the factorial
print ("The factorial of 5 is : ", end ="") 
print (math.factorial(x))

输出：

The factorial of 5 is : 120

代码#2：

# Python code to demonstrate the working of factorial()
  
# importing "math" for mathematical operations 
import math 
  
x = 5
y = 15
z = 8
  
# returning the factorial
print ("The factorial of 5 is : ", math.factorial(x))
print ("The factorial of 15 is : ", math.factorial(y))
print ("The factorial of 8 is : ", math.factorial(z))

输出：

The factorial of 5 is :  120
The factorial of 15 is :  1307674368000
The factorial of 8 is :  40320

代码 #3：如果 x 不是整数，则抛出 ValueError

# Python code to demonstrate the working of factorial()
    
# importing "math" for mathematical operations 
import math 
    
# when x is not integer
print ("math.factorial(13.7) : ", math.factorial(13.7))

输出：

ValueError: factorial() only accepts integral values