sort series with pandas in python

I selected one column from the a DataFrame, then I got a Series. How can I sort the series? I used the Series.sort(), but it doesn't work.

df = pd.DataFrame({'A': [5,0,3,8],
                    'B': ['B8', 'B9', 'B10', 'B11']})
df

    A   B
0   5   B8
1   0   B9
2   3   B10
3   8   B11

Then I selected the column 'A'

df['A']

    A
 0  5
 1  0
 2  3
 3  8

After selected 'A' column, I got a Series, but with Series.sort(), it doesn't work.

df['A'].sort()

It shows the error:

"ValueError: This Series is a view of some other array, to sort in-place you must create a copy"

So I used the Series.copy() function to copy the series, after that I sort the series, but there is no outcome.

df['A'].copy().sort()

But there is no result returned.

How can I fix the problem?