what's the inverse of the quantile function on a pandas Series?

Question

The quantile functions gives us the quantile of a given pandas series s,

E.g.

s.quantile(0.9) is 4.2

Is there the inverse function (i.e. cumulative distribution) which finds the value x such that

s.quantile(x)=4

Thanks

Answer 1

Use scipy.stats.percentileofscore:

# libs required
from scipy import stats
import pandas as pd
import numpy as np

# generate ramdom data with same seed (to be reproducible)
np.random.seed(seed=1)
df = pd.DataFrame(np.random.uniform(0, 1, (10)), columns=['a'])

# quantile function
x = df.quantile(0.5)[0]

# inverse of quantile
stats.percentileofscore(df['a'], x)