Python Challenges

last_n_chars(text, n) returns the last n characters of text. Example: last_n_chars("debugging", 3) → "ing".

Off-by-one

full_name(user) joins first, middle and last name with single spaces, and skips the middle name when there is none. Example: {"first": "Alan", "last": "Turing"} → "Alan Turing".

Null / Undefined

binary_search(nums, target) returns the index of target in a sorted list, or -1 if it is not there. Example: binary_search([1, 3, 5, 7, 9], 9) → 4.

Off-by-one

get_setting(config, key) returns the value for key, or "default" if the key is not there. Example: get_setting({"theme": "dark"}, "font") → "default".

Null / Undefined

factorial(n) returns n × (n - 1) × … × 1. Example: factorial(5) → 120. factorial(0) and factorial(1) are both 1.

Other

can_checkout(cart_total, has_valid_payment) returns True only when the cart is not empty and the payment is valid. Example: can_checkout(50, True) → True, can_checkout(50, False) → False.

Logic error

format_price(amount) returns the amount with a dollar sign. Example: format_price(5) → "$5".

Type error

countdown(n) returns a list counting down from n to 1. Example: countdown(3) → [3, 2, 1].

Infinite loop

sum_range(n) adds up every whole number from 1 to n. Example: sum_range(5) → 15 (1 + 2 + 3 + 4 + 5).

Off-by-one