python MCQ 31-45

Question 31.Why is there an error in the code and how would you fix it?

Question 32. What will the following script output? Please try to do this mentally if you can.

Question 33. Here's another similar exercise. What will the following script output? Try to do this mentally if you can.

Question 34. The following script throws a NameError in the last line saying that c is not defined. Please fix the function so that there is no error and the last line is able to print out the value of c (i.e. 1 ).

Question 35. Create a function that takes any string as input and returns the number of words for that string.

Question 36. Please download the words1.txt file from the attachment and then create a Python function that takes a text file as input and returns the number of words contained in the text file.

def count_words(filepath):
                                with open(filepath, 'r') as file:
                                    strng = file.read()
                                    strng_list = strng.split(" ")
                                    return len(strng_list)
                            print(count_words("words1.txt"))

Note: For the above script to work, you should have a file named words1.txt in the same directory with the Python script.
                        
                        Explanation: 
                        The function here takes as input a file path. If the file path is in the same directory with your Python script, you can simply pass in the file name as in the above script. If your text file is somewhere else, then you need to pass the full path when calling the function. Example:
                        
                        print(count_words("C:/Home/words1.txt"))
                        The rest of the script consists of opening the file in read  mode, loading the text into a string using read  and then splitting and counting the number of words.

Question 37. Create a function that takes a text file as input and returns the number of words contained in the text file.

def count_words(filepath):
                                  with open(filepath, 'r') as file:
                                      string = file.read()
                                      string = string.replace(",", " ")
                                      string_list = string.split(" ")
                                      return len(string_list)

print(count_words("words2.txt"))

Explanation 1:
                              This solution is like the solution of the previous exercise with the difference that before splitting 
                              we are replacing all commas with a space which will let the split method count the number of words.

Answer 2:

import re

def count_words_re(filepath):
                                  with open(filepath, 'r') as file:
                                      string = file.read()
                                      string_list = re.split(",| ", string)
                                      return len(string_list)

print(count_words_re("words2.txt"))

Explanation 2:
                              This alternative solution uses the built-in re  module which provides regular expression matching operations. 
                              We're using the split method of that module and the expression ",| " is meant to replace commas with spaces. 
                              Using methods from the re  module can be more appropriate than Python built-in methods when string operations are complicated. 
                              However, for this simple scenario the re  module could be skipped.

Question 38. The following code is supposed to print out the square root of 9, but it throws an error instead because another line before that is missing. Please fix the script so that it prints out the square root of 9.

Question 39. The script is supposed to output the cosine of angle 1 radian, but instead it is throwing an error. Please fix the code so that it prints out the expected output.

Question 40. Please try to guess what is missing in the following code and add the missing part so that the code works fine.

Question 41. Create a script that generates a text file with all letters of English alphabet inside it, one letter per line.

Question 42. Print out in each line the sum of homologous items of the two sequences.

Question 43. Create a script that generates a file where all letters of English alphabet are listed two in each line.

Question 44. Create a script that generates a file where all letters of English alphabet are listed three in each line.

import string

letters = string.ascii_lowercase + " "
                              
                              slice1 = letters[0::3]
                              slice2 = letters[1::3]
                              slice3 = letters[2::3]
                              
                              with open("letters.txt", "w") as file:
                                  for s1, s2, s3 in zip(slice1, slice2, slice3):
                                      file.write(s1 + s2 + s3 + "\n")

Explanation:
                              
                              This is like the previous exercise with the difference that we're using a different slicing step of 3 here. 
                              Another difference is that we are adding one white spaces to ascii_lowercase  
                              so that we get a string of 27 items as opposed to 26 that ascii_lowercase  provides.
                               By slicingascii_lowercase we would get two slices with a length of 9 and one slice with a length of 8. 
                              
                              That means the iteration would stop at the shortest slice so letters y and z wouldn't be written in the file.
                               That's why we add a white space so we get three slices each with a length of 9. 
                               That means we get 9 iterations and not 8 as we would get with the original ascii_lowercase  string. 
                               The 9th iteration would write letters y and z in the file.
                              
                              Note that this solution might not be the best and there are surely improvements to be made so the script works with any number of letters.

Question 45. Please create a script that generates 26 text files named a.txt, b.txt, and so on up to z.txt.

python MCQ 31-45

Answer 31.

Answer 32.

Answer 33.

Answer 34.

Answer 35.

Answer 36.

Answer 37.

Answer 38.

Answer 39.

Answer 40.

Answer 41.

Answer 42.

Answer 43.

Answer 44.

Answer 45.