Drills tagged with this skill, unpassed first. Pass them all to mark the skill ready for scenarios.
orders_in_regions(df, regions) that returns rows where df["region"] is in regions (a list of region codes).
Example. regions ["A", "C"] → rows tagged A or C, in original order.
Notes. Preserve original df order. Empty regions list → empty DataFrame.amounts_between(df, low, high) that returns rows where df["amount"] is between low and high, inclusive on both ends.
Example. amounts [10, 25, 50, 75, 100], low=25, high=75 → rows with 25, 50, 75.
Notes. Both endpoints inclusive. low == high → only rows matching that exact value. Empty result if no values qualify.emails_from_domain(df, domain) that returns rows where df["email"] contains domain as a substring (case-insensitive).
Example. domain "gmail" matches "alice@gmail.com" and "carol@GMAIL.com" both.
Notes. Case-insensitive match. No matches → empty DataFrame.