CODEWITHSUNDEEP
pythonpandas
EmJ
EmJ

Reputation: 4608

How to modify rank in pandas in python

I have a pandas dataframe as follows.

item   x1 x2 x3 x4 x5 ratings
item1   x  x  x  x  x  46
item1   x  x  x  x  x  32
item1   x  x  x  x  x  16
item1   x  x  x  x  x  6
item1   x  x  x  x  x  36
item1   x  x  x  x  x  36
item1   x  x  x  x  x  12
item1   x  x  x  x  x  13
item1   x  x  x  x  x  41
item1   x  x  x  x  x  42
item1   x  x  x  x  x  43
item1   x  x  x  x  x  3
item1   x  x  x  x  x  76
item1   x  x  x  x  x  36
item1   x  x  x  x  x  26
item1   x  x  x  x  x  12
item1   x  x  x  x  x  11
item1   x  x  x  x  x  88
item1   x  x  x  x  x  87
item1   x  x  x  x  x  78
item1   x  x  x  x  x  43
item1   x  x  x  x  x  42

Now, I want to add another column with rankings of ratings.

I did it fine using;

df = df.assign(rankings=df.rank(ascending=False))

I want to re-aggrange ranking column again and add a diffrent column to the dataframe as follows.

Is there a way to do this in pandas in python?

I am happy to provide more details if needed.

Upvotes: 2

Views: 231

Answers (1)

jezrael
jezrael

Reputation: 862661

Use integer division by 10 and add 1, last converting to integers:

df = df.assign(rankings=df['ratings'].rank(ascending=False))
df['new'] = (df['rankings'] // 10 + 1).astype(int)
print (df)
     item x1 x2 x3 x4 x5  ratings  rankings  new
0   item1  x  x  x  x  x       46       5.0    1
1   item1  x  x  x  x  x       32      14.0    2
2   item1  x  x  x  x  x       16      16.0    2
3   item1  x  x  x  x  x        6      21.0    3
4   item1  x  x  x  x  x       36      12.0    2
5   item1  x  x  x  x  x       36      12.0    2
6   item1  x  x  x  x  x       12      18.5    2
7   item1  x  x  x  x  x       13      17.0    2
8   item1  x  x  x  x  x       41      10.0    2
9   item1  x  x  x  x  x       42       8.5    1
10  item1  x  x  x  x  x       43       6.5    1
11  item1  x  x  x  x  x        3      22.0    3
12  item1  x  x  x  x  x       76       4.0    1
13  item1  x  x  x  x  x       36      12.0    2
14  item1  x  x  x  x  x       26      15.0    2
15  item1  x  x  x  x  x       12      18.5    2
16  item1  x  x  x  x  x       11      20.0    3
17  item1  x  x  x  x  x       88       1.0    1
18  item1  x  x  x  x  x       87       2.0    1
19  item1  x  x  x  x  x       78       3.0    1
20  item1  x  x  x  x  x       43       6.5    1
21  item1  x  x  x  x  x       42       8.5    1

Upvotes: 3

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