CODEWITHSUNDEEP
pythonpandas
Amit
Amit

Reputation: 793

How to replace the number in a dataframe in a particular range in Python?

I have a dataset that has a variable named 'EntrySec' and I want to replace the values if it falls in a certain range.

Entrysec
1
21
32
9
43
66

Expectation: replace all values by

10 if it falls in the range between 1-10
20 if it falls in the range of 11-20
30 if it falls in the range of 21-30 and so on

Upvotes: 2

Views: 1325

Answers (2)

Riccardo Bucco
Riccardo Bucco

Reputation: 15364

Here is a very simple solution that works for any number (it doesn't matter in which range a number is). It rounds the values of a Pandas DataFrame's column to the next ten:

df["Entrysec"] = df["Entrysec"]//10*10+10

How does it work?

  1. Perform the integer division by 10 (it basically cuts off the fractional part of the normal division). In this way you obtain the tens of a number. For example:

    • 43/10=4.3 (normal division)
    • 43//10=4 (integer division)

  2. Multiply by 10, getting the original number without its ones. For example: 4*10=40.

  3. Add 10 to get the desired result. For example, 40+10=50.

Edit

While my solution rounds a value to its next ten, the user wants to round e.g. 20 to 20 (and not 30). This can be achieved by slightly modifying my approach:

df["Entrysec"] = (df["Entrysec"]-1)//10*10+10

In this way it is possible to get the desired output. Here are some corner cases:

  • 9 is rounded to 10
  • 10 is rounded to 10
  • 11 is rounded to 20

Note that with this approach 0 is rounded to 0, as implicitly asked.

Upvotes: 6

irtazaakram
irtazaakram

Reputation: 159

Try using df.loc

import pandas as pd
df = pd.DataFrame({'Entrysec': [1, 21, 32, 9, 43, 66]})

and then 

df.loc[(df["Entrysec"] >= 1) & (df["Entrysec"] <= 10), "Entrysec"] = 10
df.loc[(df["Entrysec"] >= 11) & (df["Entrysec"] <= 20), "Entrysec"] = 20
df.loc[(df["Entrysec"] >= 21) & (df["Entrysec"] <= 30), "Entrysec"] = 30

for range of 100 we can have:

j = 1
for i in range(1,10):
    df.loc[(df["Entrysec"] >= j) & (df["Entrysec"] <= i*10), "Entrysec"] = i*10
    i = i + 1
    j = j + 10

Entrysec
0   10
1   30
2   40
3   10
4   50
5   70

Upvotes: 3

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