Exercises¶

1. • Question
   • Answer

   Write a program that allows the user to enter a string. It then prints a table of the letters of the alphabet in alphabetical order which occur in the string together with the number of times each letter occurs. Case should be ignored. A sample run of the program might look this this:

   Please enter a sentence: ThiS is String with Upper and lower case Letters.
   a  2
   c  1
   d  1
   e  5
   g  1
   h  2
   i  4
   l  2
   n  2
   o  1
   p  2
   r  4
   s  5
   t  5
   u  1
   w  2
   $
   

   Run Save Load

   
   

   (ex_11_01)

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   x = input("Enter a sentence") x = x.lower() # convert to all lowercase alphabet = 'abcdefghijklmnopqrstuvwxyz' letter_count = {} # empty dictionary for char in x: if char in alphabet: # ignore any punctuation, numbers, etc if char in letter_count: letter_count[char] = letter_count[char] + 1 else: letter_count[char] = 1 keys = letter_count.keys() keys.sort() for char in keys: print(char, letter_count[char])

   (q1_answer)

2. Give the Python interpreter’s response to each of the following from a continuous interpreter session:

   1. >>> d = {'apples': 15, 'bananas': 35, 'grapes': 12}
      >>> d['banana']
      

   2. >>> d['oranges'] = 20
      >>> len(d)
      

   3. >>> 'grapes' in d
      

   4. >>> d['pears']
      

   5. >>> d.get('pears', 0)
      

   6. >>> fruits = d.keys()
      >>> fruits.sort()
      >>> print(fruits)
      

   7. >>> del d['apples']
      >>> 'apples' in d
      

   Be sure you understand why you get each result. Then apply what you have learned to fill in the body of the function below:

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   def add_fruit(inventory, fruit, quantity=0): pass # make these tests work... # new_inventory = {} # add_fruit(new_inventory, 'strawberries', 10) # test('strawberries' in new_inventory, True) # test(new_inventory['strawberries'], 10) # add_fruit(new_inventory, 'strawberries', 25) # test(new_inventory['strawberries'] , 35)

   (q2_dict_answer)

3. • Question
   • Answer

   Here’s a table of English to Pirate translations

   English	Pirate
   sir	matey
   hotel	fleabag inn
   student	swabbie
   boy	matey
   madam	proud beauty
   professor	foul blaggart
   restaurant	galley
   your	yer
   excuse	arr
   students	swabbies
   are	be
   lawyer	foul blaggart
   the	th’
   restroom	head
   my	me
   hello	avast
   is	be
   man	matey

   Write a program that asks the user for a sentence in English and then translates that sentence to Pirate.

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   (ex_11_04)

   Run Save Load Show in Codelens

   
   

   pirate = {} pirate['sir'] = 'matey' pirate['hotel'] = 'fleabag inn' pirate['student'] = 'swabbie' pirate['boy'] = 'matey' pirate['restaurant'] = 'galley' # and so on sentence = input("Please enter a sentence in English") psentence = [] words = sentence.split() for aword in words: if aword in pirate: psentence.append(pirate[aword]) else: psentence.append(aword) print(" ".join(psentence))

   (ch11_q5_answer)