Fill Out Missing Records

[Wong]

Got an interesting ask today. There’s data like below. Each patient should have 3 visit records but there are some missing observations.

Patient Visit Duration

1 1 60

1 2 55

1 3 21

2 2 44

2 3 15

3 2 55

Can you fill out the data which will be like the following?

Patient Visit Duration

1 1 60

1 2 55

1 3 21

2 1 .

2 2 44

2 3 15

3 1 .

3 2 55

3 3 .

It is very simple with SQL cross join.

How about SAS and Python? Can you do it?