How to create a unique sequence number for each row?

[Datura]

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In real work, we often need to have a unique sequence ID for each row, or for each row in each group, such as 1, 2, 3……………… N. For example, for our RFM project, we need such a Sequence ID for segmentation.

It is very easy to do it in SAS by using the SUM statement, however, not easy in R and Python. Can you work out the code for creating such a sequence ID for each row, and for each row of each group? How many different methods you can figure out?

• This discussion was modified 4 years, 2 months ago by  Datura.

[norahx]

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You mean calculate the sum of each row to generate a new column?

[Justin]

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Not a sum, just a sequence ID. In SAS, we can use the SUM statement to create a sequence ID or a cumulative sum.

[Tundra.L]

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If this is what you mean:

normally I used following methods to assign labels for segments

1. customer function to define the segment, the labels will be numeric data

2.cut() or qcut (), the labels will be category data

3. ceil() for special situation, the labels will be numeric data

[Justin]

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It’s too complicated, we have a better way.

[Tundra.L]

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can you show us please?