- You can use the
pandas.DataFrame.quantile() function.
- If you look at the API for
quantile(), you will see it takes an argument for how to do interpolation. If you want a quantile that falls between two positions in your data:
- ‘linear’, ‘lower’, ‘higher’, ‘midpoint’, or ‘nearest’.
- By default, it performs linear interpolation.
- These interpolation methods are discussed in the Wikipedia article for percentile
import pandas as pd
import numpy as np
# sample data
np.random.seed(2023) # for reproducibility
data = {'Category': np.random.choice(['hot', 'cold'], size=(10,)),
'field_A': np.random.randint(0, 100, size=(10,)),
'field_B': np.random.randint(0, 100, size=(10,))}
df = pd.DataFrame(data)
df.field_A.mean() # Same as df['field_A'].mean()
# 51.1
df.field_A.median()
# 50.0
# You can call `quantile(i)` to get the i'th quantile,
# where `i` should be a fractional number.
df.field_A.quantile(0.1) # 10th percentile
# 15.6
df.field_A.quantile(0.5) # same as median
# 50.0
df.field_A.quantile(0.9) # 90th percentile
# 88.8
df.groupby('Category').field_A.quantile(0.1)
#Category
#cold 28.8
#hot 8.6
#Name: field_A, dtype: float64
df
Category field_A field_B
0 cold 96 58
1 cold 22 28
2 hot 17 81
3 cold 53 71
4 cold 47 63
5 hot 77 48
6 cold 39 32
7 hot 69 29
8 hot 88 49
9 hot 3 49