useful_functions.py

# Example 1: Verifies that the given number is an integer (not just the type). Works for floats too.
def is_int(x):
  if x - round(x) == 0:
    return True
  else:
    return False

# Example 2: Summarize all digits for a given number (non negative)
def digit_sum(n):
  result = 0
  s = str(n)
  for digit in s:
    result += int(digit)
  return result

# Example 3: Summarize all digits for a given number using modulo and floor division (non negative)
def digit_sum(n):
  result = 0
  while (n % 10) > 0:
      result += n % 10
      n = n // 10
  return result

# Example 4. Factorial for non negative integer values
def factorial(x):
  result = 1
  while x > 0:
    result *= x
    x -= 1
  return result

# Example 5: Finds if a given number is prime or not (tired version)
def is_prime(x):
  if x <= 1:
    return False
  elif x == 2:
    return True
  else:
    result = True
    for n in range(2, x):
      if x % n == 0:
        result = False
    return result

# Example 6: Reverse string
def reverse(text):
  lst = []
  for char in text:
    lst.insert(0,char)
  return "".join(lst)

# Example 7: Anti vowels funtion
def anti_vowel(text):
  # Lowercase vowels
  result = text.replace('a', '')
  result = result.replace('e', '')
  result = result.replace('i', '')
  result = result.replace('o', '')
  result = result.replace('u', '')
  # Uppercase vowels
  result = result.replace('A', '')
  result = result.replace('E', '')
  result = result.replace('I', '')
  result = result.replace('O', '')
  result = result.replace('U', '')
  return result

# Example 8: Calculating Scrabble score
score = {"a": 1, "c": 3, "b": 3, "e": 1, "d": 2, "g": 2, 
         "f": 4, "i": 1, "h": 4, "k": 5, "j": 8, "m": 3, 
         "l": 1, "o": 1, "n": 1, "q": 10, "p": 3, "s": 1, 
         "r": 1, "u": 1, "t": 1, "w": 4, "v": 4, "y": 4, 
         "x": 8, "z": 10}

def scrabble_score(word):
  word_score = 0
  for char in word:
    word_score += score[char.lower()]
  return word_score

# Example 9: Couting appearences of an item in a list
def count(sequence, item):
  hits = 0
  for x in sequence:
    if x == item:
      hits += 1
  return hits

# Example 10: Remove all odd numbers for a given list
def purify(arg):
  even_numbers = []
  for n in arg:
    if (n % 2 == 0):
      even_numbers.append(n)
  return even_numbers

# Example 11: Return the product of all items for a given list
def product(arg):
  result = 1
  for i in range(0, len(arg)):
    result *= 1 * arg[i]
  return result

# Example 12: Remove duplicates from a list
def remove_duplicates(arg):
    sorted_list = sorted(arg)
    new_list = []
    for i in range(0, len(sorted_list)):
        if (i == 0):
            new_list.append(sorted_list[i])
        else:
            if (sorted_list[i] != new_list[len(new_list)-1]):
                new_list.append(sorted_list[i])
    return new_list

# Example 13: The median is the middle number in a sorted sequence of numbers
def median(arg):
  sorted_list = sorted(arg)
  if (len(sorted_list) % 2 != 0):
    middle_item = len(sorted_list) / 2
    return sorted_list[middle_item]
  else:
    middle_item_1 = sorted_list[(len(sorted_list) / 2) - 1]
    middle_item_2 = sorted_list[len(sorted_list) / 2]
    return (middle_item_1 + middle_item_2) / 2.0

# Example 14: Return all the reserved words in Python language
import builtins

for x in dir(builtins):
    print(x)