如何删除最后一个数字后的多余空格

Question

In my program, I am printing an extra space after the last number. How can I remove that?

def fibonacci(n):
a = 0
b = 1
if n == 1:
    print(a, end=' ')
else:    
    print(a, end=' ')
    print(b, end=' ')
    for i in range(2, n):
        c = a + b
        a = b
        b = c
        print(c, end=' ')

fibonacci(int(input()))

Input: 5
Output: 0 1 1 2 3
I'm printing an extra space after the last number.

Answer 1

Separate the process of generating the numbers, from the process of printing them. (This is something you should do anyway , but it also happens in this case to make it easier to solve the problem.) For example, we can use a generator to yield multiple values. Notice that we don't need to handle any special cases, and we can also use the pack-unpack idiom for multiple assignments :

def fibonacci(n):
    a, b = 1, 1
    for i in range(n):
        yield a
        a, b = b, a + b

Now we can display these values separated by spaces by using the sep arator for print rather than the end , and passing each of the values as a separate argument. To do that, we need explicit unpacking with * . It looks like:

print(*fibonacci(10), sep=' ')

And we get the desired result, with no trailing space:

1 1 2 3 5 8 13 21 34 55

Answer 2

A @Carcigenicate suggested you can use a list,

In the following code have just replaced the print statements with list.append()

def fibonacci(n):
    l1=[]
    a = 0
    b = 1
    if n == 1:
        print(a, end=' ')
        l1.append(str(a))

    else:    
        l1.append(str(a))
        l1.append(str(b))
        for i in range(2, n):
            c = a + b
            a = b
            b = c
            l1.append(str(c))
    tr=" ".join(l1)
    print(tr,end='')
    print('h',end='')

fibonacci(int(input()))

output:

8
0 1 1 2 3 5 8 13h

as you can see in the output there is no extra space after last number 13 and i have printed h after 13 .

hope this helps you!