Data types and variables
# Google is encouraged. Type what you find, do not paste it.
# ---- Part 1: numbers ----
def square(n):
"""Return n multiplied by itself.
square(5) → 25
square(-3) → 9
Search: "python power operator".
"""
raise NotImplementedError
def average(a, b):
"""Return the mean of two numbers.
average(2, 5) → 3.5
average(4, 4) → 4.0
Search: "python division float".
"""
raise NotImplementedError
# ---- Part 2: strings ----
def last_char(text):
"""Return the last character of text.
last_char("code") → e
last_char("") → None (decide what to return for an empty string)
Search: "python string index".
"""
raise NotImplementedError
# ---- Part 3: conversion ----
def to_number(text):
"""Convert text to a number.
to_number("42") → 42
to_number("3.5") → 3.5
Search: "python string to int".
"""
raise NotImplementedError
def is_number(text):
"""Return True when text holds a valid number.
is_number("42") → True
is_number("-7") → True
is_number("abc") → False
Search: "python check if string is a number".
"""
raise NotImplementedError