反转 python 中给定字符串中的单词

Question

I have written the code in python it works fine if I give integer as an input but it does not when string is given.

Example -

Input:

2
i.like.this.program.very.much
pqr.mno

Expected Output:

much.very.program.this.like.i
mno.pqr

But the output which I get is same as input. The string is not getting reversed. The code I have written is -

t=int(input())
for i in range(t):
    string1=input()
    li1=string1.split()
    li2=li1[::-1]
    output=' '.join(li2)
    print(output)

After running for the above input I get -

Output:

i.like.this.program.very.much
pqr.mno

Answer 1

Cause of Wrong Output

The reason your program doesn't work correctly is because you are trying to split the string at space character which is the default for split() when no parameter is specified. But you are really looking to split your string at '.' character.

So when you try string1.split() , the list you get is -

['i.like.this.program.very.much']

while what we really want to get the correct output is -

['i', 'like', 'this', 'program', 'very', 'much']

which we get correctly using string1.split('.') , that is splitting the string at . character and then reversing the string. Do note that while joining the string, we would have to join it using . as well.

---

So you should modify your code as follows.

Correct Code -

t=int(input())
for i in range(t):
    string1=input()
    li1=string1.split('.') #<-- Notice the parameter specified here. It will now split at `.` character
    li2=li1[::-1]          # Reverse the list
    output='.'.join(li2)   # Convert back into string. Again notice, we are joining at . character to get expected output
    print(output)

Input:

2
i.like.this.program.very.much
pqr.mno

Output:

much.very.program.this.like.i
mno.pqr

Hope this helps !

Answer 2

s = input("Enter string here = ")
l1=s.split
l1.reverse()
print(l1)