How to append strings to the column of a Dataframe from another array in Pandas?

I have a Dataframe that looks like below

                ip  metric
0       10.10.20.9       0
1       10.10.1.25       0
2       10.1.13.45       0
3     10.1.100.101       0
4      10.1.100.11       0
5      10.11.2.100       0
6       10.1.2.151       0
7       10.1.2.184       0
8      10.1.20.185       0

I want to append some strings to the ip column picked from an array like so

arr = ["(0)", "(1)", "(2)", "(3)", "(4)", "(5)", "(6)", "(7)", "(8)"]

                ip  metric
0    10.10.20.9(0)       0
1    10.10.1.25(1)       0
2    10.1.13.45(2)       0
3  10.1.100.101(3)       0
4   10.1.100.11(4)       0
5   10.11.2.100(5)       0
6    10.1.2.151(6)       0
7    10.1.2.184(7)       0
8   10.1.20.185(8)       0

You can see I took items from the array and added to the values of the ip column.

Now I know how to add a string to the column of a Dataframe by doing something like below

df["ip"] = df["ip"].astype(str) + '%'

But I can't figure out how to add items from an array to the Dataframe column. Any idea how this can be done?

As your array has the same length of your DataFrame, you can concatenate strings:

df['ip'] += arr
print(df)

# Output
                ip  metric
0    10.10.20.9(0)       0
1    10.10.1.25(1)       0
2    10.1.13.45(2)       0
3  10.1.100.101(3)       0
4   10.1.100.11(4)       0
5   10.11.2.100(5)       0
6    10.1.2.151(6)       0
7    10.1.2.184(7)       0
8   10.1.20.185(8)       0

Try using a lambda function

df['ip'] = df['ip'].apply(lambda x: str(x) + "%")