Using python to generate unique IDs

Question

How should I assign a unique ID (UID) to a group of rows and a different UID where there is a sudden jump in ID values. For example; assign "1" to ID values ranging from 122 to 125 and a UID of "2" where ID values range from 507 to 511 in the table below.

Name	ID	UID
T1	122
T1	123
T1	124
T1	125
T1	507
T1	508
T1	509
T1	510
T1	511

To be honest i don't know where to start from.

Answer 1

You do not want an unique id, but just a group id, where a group is a set of rows with consecutive ID values. Assuming pandas, you could use shift() to identify consecutive values, and then cumsum() to automatically build a group id :

df['UID'] = (df['ID'] != df['ID'].shift() + 1).cumsum()

It gives as expected:

df
  Name   ID  UID
0   T1  122    1
1   T1  123    1
2   T1  124    1
3   T1  125    1
4   T1  507    2
5   T1  508    2
6   T1  509    2
7   T1  510    2
8   T1  511    2