问题
Q. ) 1 + 1 / 2! + 1/ 3! + ¼! + ….....
The output of the following program is always 1.0. I'm a python beginner. Please tell me what's wrong? Please suggest any other methods to make this program better.
No inbuilt functions, please. I want to do this manually.
n=int(raw_input("Enter number of terms : "))
d=0 #to sum all terms, initial value is 0
while n>0:
j=n #we start by taking factorial of the last term
s=1 #to multiply to find factorial
while j>0:
s=s*j #number gets multiplied to s and stored in s
j=j-1 #number is decreased until it reaches 0
n=n-1 #we will keep finding factorial until the very first term, i.e. 1 is reached
x=float(1/s) #to find reciprocal of the factorial we just found in floating point
d=d+x #adding to final sum
print "Sum of 1+1/2!+1/3!+1/4!+.... is ",d #printing
回答1:
You need to use float somewhere in your division. I just make you "s" a float.
n=int(raw_input("Enter number of terms : "))
d=0 #to sum all terms, initial value is 0
while n>0:
j=n #we start by taking factorial of the last term
s=float(1) #to multiply to find factorial
while j>0:
s=s*j #number gets multiplied to s and stored in s
j=j-1 #number is decreased until it reaches 0
n=n-1 #we will keep finding factorial until the very first term, i.e. 1 is reached
x=1/s #to find reciprocal of the factorial we just found in floating point
d=d+x #adding to final sum
print "Sum of 1+1/2!+1/3!+1/4!+.... is ",d #printing
来源：https://stackoverflow.com/questions/31323495/1-1-2-1-3-%c2%bc-finding-sum