Storing data/output from a loop

[Jason613]

I have tried using the append function along with some other changes, and it outputs an error.

qxqy=input("Position of Queenie: ").split()
qx=int(qxqy[0])
qy=int(qxqy[1])
n=input("Number of puppies: ")
n=int(n)
list=[]
countn=1
for countn in range(1,n+1): 
    countn=str(countn)
    pxpy_countn=input("Position of Puppy "+countn+": ").split()
    px_countn=int(pxpy_countn[0])
    py_countn=int(pxpy_countn[1])
    if abs(px_countn-qx)+abs(py_countn-qy)>10:
        list=list.append(countn)
print("and".join(list))

The error is as follow:

Output:
Position of Queenie: 2 1
Number of puppies: 4
Position of Puppy 1: 10 1
Position of Puppy 2: 14 -2
Position of Puppy 3: 1 3
Position of Puppy 4: 0 4
Traceback (most recent call last):
File "main.py", line 15, in <module>
print("and".join(list))
TypeError: can only join an iterable

So I have more questions.
1) What does the error means? How could I fix the error?
2) I tried to print the list outside of the loop, and the output is "none". What's wrong with my list?
3) Could you elaborate a bit more about the list and append example on #2?
Thanks for your help.