Question

Lesson Assignment

There are 13 questions regarding slicing. The first 10 are required to pass. The last 3 are extra credit.

You will place all your answers in the lesson.py tab. Select that tab and take a look at how it's done.

For your answers, each function (already defined) returns a tuple:

• the first item is the answer using index notation (e.g. text[16:20])

• the second item is the answer using slice notation (e.g. slice(16,20,None))

• the numbers you use for the slice function should be the same (you can use None for any missing indices to the slice function) so don't overthink it!

• when you solve each question, do NOT use the slice object. It's only used for the testing framework for verification.

You can test your code before submitting by running the following (not required, but helpful for debugging) code:

import slicetest

# run the tests over questions in lesson.py

print("total correct", slicetest.do_tests())

Question 1 (already finished)

Extract: "Data"

From: "Introduction to Data Science"

def question1(text):

return (text[16:20], slice(16,20,1))

Notes and hints:

• 'extract' means return the substring that is to be 'extracted' (i.e. removed) from the 'From' text.

• if you want to debug your answers, just do the following (in main.py)

import lesson as ans

result = ans.question1("Introduction to Data Science")

print(result[0] == 'Data') # looking for True

• you can also test each part of your answer:

expect = "Data"

word = "Introduction to Data Science"

s1 = slice(16,20,None)

value = word[s1]

if (value != expect):

print("Bad Slice", expect, value)

value = word[16:20]

if (value != expect):

print("Bad Index", expect, value)

• In each of your answers, you should ONLY use the slice function as part of the final return and you must use the parameter text in the return statement.

def some_answer(text):

idx = some_calculation()

return (text[idx:20], slice(idx,20,1))

Bonus: ideally, you should solve each of these without any hardcoded numbers other than the step amount:

Extract: "Data"

From: "Introduction to Data Science"

def question1(text):

word = 'Data'

wl = len(word)

idx = text.find(word)

return (text[idx:idx+wl], slice(idx, idx+wl, 1))

Question 2:

Extract: "ar"

From: "Orange"

def question2(text):

return (?,?)

Question 3:

Extract: "Oa"

From: "Orange"

def question3(text):

return (?,?)

Question 4:

Extract: "ence"

From: "Introduction to Data Science"

def question4(text):

return (?,?)

Question 5:

Extract: "ecne"

From: "Introduction to Data Science"

def question5(text):

return (?,?)

Questions 6 through 10 involve manipulating text from a horror book:

My Book, by mike Chapter 1: set up The little boy in bed was scared. Chapter 2: suspense "Daddy, daddy there's a monster under my bed." Chapter 3: climax The father then looked under the bed .. and saw his son. Chapter 4: resolution "Daddy, daddy, someone's in my bed!" (the end) About the author: a first time novelist

Notes and Hints:

• the contents of the book is everything from 'Chapter 1' until but not including '(the end)'.

• if you find yourself counting the characters, you need to rethink your solution. Use Python to get the indices, not your fingers (see documentation on find)

• test each part of your answer (see previous hints)

• you should NOT need to add text to any of these. If you find yourself wanting to add periods, newlines, etc, you are on the wrong path.

• 'remove' means return the book but without the part requested to be removed.

• 'extract' means return the part of the book that is to be 'extracted' (i.e. removed)

• The text is also in the variable book (found in the module slicetest) if you want to work with the book directly:

print(slicetest.book)

Question 6:

Remove: remove the front matter of the book

From: the text of the book

the front matter is the stuff before the contents

def question6(text):

return (?,?)

Question 7:

Remove: remove the back matter of the book

From: the text of the book

the back matter is the stuff after the contents

def question7(text):

return (?,?)

Question 8:

Extract: the front matter of the book

From: the text of the book

def question8(text):

return (?,?)

Question 9:

Extract: the back matter of the book (About the author)

From: the text of the book

Note: do NOT include (the end)\n

def question9(text):

return (?,?)

Question 10:

Extract: the contents of the book

From: the text of the book

def question10(text):

return (?,?)

Extra Credit:

The last 3 questions want you to extract a hidden message from a gibberish of text.

If you want to skip this part put the following line of code in lesson.py:

skip_extra = True

Question 11:

Extract: I Love Python

From: slicetest.mystery11 variable

def question11(text):

return (?,?)

Question 12:

Extract: Data Science Rocks

From: slicetest.mystery12 variable

def question12(text):

return (?,?)

Question 13:

Extract: Info 490 is fun

From: slicetest.mystery13 variable

def question13(text):

return (?,?)

Answer 1

ANSWER:

• As per Chegg's rules, I am bound to answer only the first four parts of the question. As function question1 is already answered, I have provided the solution for functions question2 to question5 along with their testing.
• I have provided properly commented code in both text and image format so it will be easy for you to copy the code as well as check for correct indentation.
  • The functions and testing are in the different files-
    • lesson.py - Consist of all above functions
    • main.py - Testing part of the code
• I have provided the output image of the code so it will be easy for you to cross check for correct output of the code.
• Have a nice and healthy day !!

CODE TEXT

a. lesson.py

# function question2
def question2(text):
   word = 'ar'
   wl = len(word)
   # finding word in reversed text, reversed by reverse indexing
   idx = text[::-1].find(word)
   # using fetched index and reversed indexing to find word
   return text[-(idx+1):-(idx+1+wl):-1],slice(-(idx+1),-(idx+1+wl),-1)

# function question3
def question3(text):
   word = "Oa"
   wl = len(word)
   # finding word in 2 char slided string
   idx = text[::2].find(word)
   # doubling fetched index to match index in original string
   return text[idx*2:(idx+wl)*2:2],slice(idx*2,(idx+wl)*2,2)

def question4(text):
   # This can be solved using question1 solution
   # but here I am hardcoding length to use the negative indexing
   wl = 4
   return text[-wl:],slice(-wl,None,None)

def question5(text):
   # This can be solved using question2 solution
   # but here I am hardcoding length to use the reverse slicing
   wl = 4
   return text[-1:-(wl+1):-1],slice(-1,-(wl+1),-1)

b. main.py

## Importing
import lesson as ans

## Testing function question2
print('Test question2')
text = "Orange"
expect = "ar"
text_slice,s1 = ans.question2(text)
value=text[s1]
if text[s1] != expect:
   print("Bad Slice",expect,value)
else:
   print('Correct Slice')
if text_slice != expect:
   print("Bad Index",expect,value)
else:
   print("Correct Index")

## Texting function question3
print('Test question3')
text = "Orange"
expect = "Oa"
text_slice,s1 = ans.question3(text)
value=text[s1]
if text[s1] != expect:
   print("Bad Slice",expect,value)
else:
   print('Correct Slice')
if text_slice != expect:
   print("Bad Index",expect,value)
else:
   print("Correct Index")

## Texting function question3
print('Test question4')
text = "Introduction to Data Science"
expect = "ence"
text_slice,s1 = ans.question4(text)
value=text[s1]
if text[s1] != expect:
   print("Bad Slice",expect,value)
else:
   print('Correct Slice')
if text_slice != expect:
   print("Bad Index",expect,value)
else:
   print("Correct Index")

## Texting function question3
print('Test question5')
text = "Introduction to Data Science"
expect = "ecne"
text_slice,s1 = ans.question5(text)
value=text[s1]
if text[s1] != expect:
   print("Bad Slice",expect,value)
else:
   print('Correct Slice')
if text_slice != expect:
   print("Bad Index",expect,value)
else:
   print("Correct Index")

CODE IMAGES

a. lesson.py

b. main.py

OUTPUT IMAGE