Is narcissistic

maths/average_welford.py

@@ -0,0 +1,21 @@
+def average_welford(values: list) -> float:
+  """
+    >>> average_welford([1, 2, 3, 4, 5])
+    3.0
+    >>> average_welford([1.2329435, 2.209462409, 3.230925, 4.47626462, 5.2938759204])
+    3.2886942898799996
+    >>> average_welford([-57386462.2329435, 2246262.209462409, 4632463.230925, 856737354.47626462, -243664265.2938759204])
+    112513070.4779665
+  """
+  avg = 0.0
+  """while looping through the list,
+     we calculate the average of the
+     current element and the average
+     of the elements before it"""
+  for index in range(0, len(values)):
+    avg += (values[index]-avg)/(index+1)
+  return avg
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()

maths/is_narcissistic.py

@@ -0,0 +1,24 @@
+def is_narcissistic(i: int) -> bool:
+
+  """
+    >>> is_narcissistic(1527)
+    False
+    >>> is_narcissistic(-1527)
+    False
+    >>> is_narcissistic(153)
+    True
+    >>> is_narcissistic("153")
+    True
+  """
+
+  """In number theory, a narcissistic number is a number that is 
+  the sum of its own digits each raised to the power of the number of digits.
+  this alogrithm finds out if given number 'i' is narcissistic or not"""
+
+  i = abs(int(i))
+  return sum([int(char)**len(str(i)) for char in str(i)]) == i
+
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()

strings/censor.py

@@ -0,0 +1,26 @@
+def censor(txt: str, word: str) -> str:
+    """
+    >>> censor("one two three", "one")
+    *** two three
+    >>> censor("email, password", "password")
+    email, ********
+    >>> censor("pin: 2536", "2536")
+    pin: ****
+
+    """
+
+    txt_lst = txt.split()
+    #here we loop through a list which consists of words from the text we should censor
+    for index, word1 in enumerate(txt_lst):
+      if word1 == word:
+        txt_lst[index] = "*" * len(word1)
+    txt = ""
+    #here we combine all of the split words in txt_lst into one string
+    for word1 in txt_lst:
+      txt += word1 + " "
+    txt = txt[:-1]
+    print(txt)
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()

strings/decrypt.py

@@ -0,0 +1,38 @@
+def decrypt(txt: str, symbol: str) -> str:
+  """
+  >>> decrypt("o$ne", "$")
+  one
+  >>> decrypt("dec@rypt", "@")
+  decrypt
+  >>> decrypt("p#ython cod#e", "#")
+  python code
+
+  """
+  #here we split the string we need to decypher into a list
+  txt_lst = txt.split()
+  res_str = ""
+  #we create a for loop which loops through the newly created list
+  for word1 in txt_lst:
+    #here we convert the current word we got through the loop into a list of charachters
+    word1_lst = list(word1)
+    #we loop through each charachter in the newly created list of charachters form the word we are looping throuh
+    for char1 in word1_lst:
+      #we set a condition, where if the symbol the loop is currently on corresponds to the symbol we need to remove, we stop on it and examine it
+      if char1 == symbol:
+        #we find the charachters index from the word
+        indx = word1.index(char1)
+        #we remove the list (the list which contains every element and characahter from the word we are looping throuh) element with the same index from the list.
+        word1_lst[indx] = ""
+    res_wrd = ""
+    #we loop throuh the list containing all the charachters from the word, and append those charachters to a new string
+    for char1 in word1_lst:
+      res_wrd += char1
+    #here we add the newly created, decyphered word to a new string which will contain our full result
+    res_str += res_wrd + " "
+  res_str = res_str[:-1]
+  #and here we print out the final result
+  print(res_str)
+
+if __name__ == "__main__":
+  import doctest
+  doctest.testmod()