🐼 One Pandas Function That Can Save You From Ugly if/else

Suppose you want to classify customers:

spending >= 1000 → VIP
spending >= 500  → Regular
otherwise        → Low

You could write a complicated function.
Or:

import numpy as np

df["segment"] = np.select(
    [
        df["spending"] >= 1000,
        df["spending"] >= 500
    ],
    [
        "VIP",
        "Regular"
    ],
    default="Low"
)

Now the rules are visible directly in the code.

This becomes especially useful when you have several conditions.