Warmup-1.md

CodingBat -> Python -> Warmup-1

sleep_in

The parameter weekday is True if it is a weekday, and the parameter vacation is True if we are on vacation. We sleep in if it is not a weekday or we're on vacation. Return True if we sleep in.

sleep_in(False, False) → True
sleep_in(True, False) → False
sleep_in(False, True) → True

def sleep_in(weekday, vacation):
  return weekday == False or vacation == True

monkey_trouble

We have two monkeys, a and b, and the parameters a_smile and b_smile indicate if each is smiling. We are in trouble if they are both smiling or if neither of them is smiling. Return True if we are in trouble.

monkey_trouble(True, True) → True
monkey_trouble(False, False) → True
monkey_trouble(True, False) → False

def monkey_trouble(a_smile, b_smile):
  return a_smile == b_smile

sum_double

Given two int values, return their sum. Unless the two values are the same, then return double their sum.

sum_double(1, 2) → 3
sum_double(3, 2) → 5
sum_double(2, 2) → 8

def sum_double(a, b):
  if a == b :
    return 2 * (a + b)
  else :
    return a + b

diff21

Given an int n, return the absolute difference between n and 21, except return double the absolute difference if n is over 21.

diff21(19) → 2
diff21(10) → 11
diff21(21) → 0

def diff21(n):
  if n > 21 :
    return 2 * abs(n - 21)
  else :
    return abs(n - 21)

parrot_trouble

We have a loud talking parrot. The "hour" parameter is the current hour time in the range 0..23. We are in trouble if the parrot is talking and the hour is before 7 or after 20. Return True if we are in trouble.

parrot_trouble(True, 6) → True
parrot_trouble(True, 7) → False
parrot_trouble(False, 6) → False

def parrot_trouble(talking, hour):
  return talking and (hour < 7 or hour > 20)

makes10

Given 2 ints, a and b, return True if one if them is 10 or if their sum is 10.

makes10(9, 10) → True
makes10(9, 9) → False
makes10(1, 9) → True

def makes10(a, b):
  return a == 10 or b == 10 or a + b == 10

near_hundred

Given an int n, return True if it is within 10 of 100 or 200. Note: abs(num) computes the absolute value of a number.

near_hundred(93) → True
near_hundred(90) → True
near_hundred(89) → False

def near_hundred(n):
  return abs(200 - n) <= 10 or abs(100 - n) <= 10

pos_neg

Given 2 int values, return True if one is negative and one is positive. Except if the parameter "negative" is True, then return True only if both are negative.

pos_neg(1, -1, False) → True
pos_neg(-1, 1, False) → True
pos_neg(-4, -5, True) → True

def pos_neg(a, b, negative):
  if negative:
    return a < 0 and b < 0
  else:
    return (a < 0 and b > 0) or (a > 0 and b < 0)

not_string

Given a string, return a new string where "not " has been added to the front. However, if the string already begins with "not", return the string unchanged.

not_string('candy') → 'not candy'
not_string('x') → 'not x'
not_string('not bad') → 'not bad'

def not_string(str):
  if len(str) >= 3 and str[:3] == "not":
    return str
  else:
    return "not " + str

missing_char

Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0..len(str)-1 inclusive).

missing_char('kitten', 1) → 'ktten'
missing_char('kitten', 0) → 'itten'
missing_char('kitten', 4) → 'kittn'

def missing_char(str, n):
  return str[:n] + str[n + 1:]

front_back

Given a string, return a new string where the first and last chars have been exchanged.

front_back('code') → 'eodc'
front_back('a') → 'a'
front_back('ab') → 'ba'

def front_back(str):
  if len(str) < 2:
    return str
  else:
    return str[len(str) - 1] + str[1:len(str) - 1] + str[0]

front3

Given a string, we'll say that the front is the first 3 chars of the string. If the string length is less than 3, the front is whatever is there. Return a new string which is 3 copies of the front.

front3('Java') → 'JavJavJav'
front3('Chocolate') → 'ChoChoCho'
front3('abc') → 'abcabcabc'

def front3(str):
  s = str[:3] 
  return s + s + s