[FIXED] Add the missing numbers in the table in order

Issue

I need modify a csv file with pandas. I have the following table:

Interface   Description
1           Used
2           Used
3           Used
4           Used
6           Used
8           Used
12          Used
17          Used

I need to match the "Interface" column with a range of 1, 20, complete the table with the missing numbers and place the word "free" in the "Description" column and order it like this:

Interface   Description
1           Used
2           Used
3           Used
4           Used
5           free
6           Used
7           free
8           Used
9           free
10          free
11          free
12          Used
13          free
14          free
15          free
16          free
17          Used
18          free
19          free
20          free

Solution

Use merge in combination with fillna

df = pd.DataFrame({
    'Interface': [1, 2, 3, 4, 6, 8, 12, 17],
    'Description': 'Used'})
df2 = pd.DataFrame({'Interface': range(1, 21)}).merge(df, how="left").fillna("free")

Answered By - bitflip