Python Institute Python Institute Certifications PCEP-30-02 Questions & Answers

• Question 21:

  What is true about tuples? (Select two answers.)

  A. Tuples are immutable, which means that their contents cannot be changed during their lifetime.

  B. The len { } function cannot be applied to tuples.

  C. An empty tuple is written as { } .

  D. Tuples can be indexed and sliced like lists.

  Correct Answer: AD

  Explanation: Tuples are one of the built-in data types in Python that are used to store collections of data. Tuples have some characteristics that distinguish them from other data types, such as lists, sets, and dictionaries. Some of these characteristics are: Tuples are immutable, which means that their contents cannot be changed during their lifetime. Once a tuple is created, it cannot be modified, added, or removed. This makes tuples more stable and reliable than mutable data types. However, this also means that tuples are less flexible and dynamic than mutable data types. For example, if you want to change an element in a tuple, you have to create a new tuple with the modified element and assign it to the same variable12 Tuples are ordered, which means that the items in a tuple have a defined order and can be accessed by using their index. The index of a tuple starts from 0 for the first item and goes up to the length of the tuple minus one for the last item. The index can also be negative, in which case it counts from the end of the tuple. For example, if you have a tuple t = ("a", "b", "c"), then t[0] returns "a", and t[- 1] returns "c"12 Tuples can be indexed and sliced like lists, which means that you can get a single item or a sublist of a tuple by using square brackets and specifying the start and end index. For example, if you have a tuple t = ("a", "b", "c", "d", "e"), then t[2] returns "c", and t[1:4] returns ("b", "c", "d"). Slicing does not raise any exception, even if the start or end index is out of range. It will just return an empty tuple or the closest possible sublist12 Tuples can contain any data type, such as strings, numbers, booleans, lists, sets, dictionaries, or even other tuples. Tuples can also have duplicate values, which means that the same item can appear more than once in a tuple. For example, you can have a tuple t = (1, 2, 3, 1, 2), which contains two 1s and two 2s12 Tuples are written with round brackets, which means that you have to enclose the items in a tuple with parentheses. For example, you can create a tuple t = ("a", "b", "c") by using round brackets. However, you can also create a tuple without using round brackets, by just separating the items with commas. For example, you can create the same tuple t = "a", "b", "c" by using commas. This is called tuple packing, and it allows you to assign multiple values to a single variable12 The len() function can be applied to tuples, which means that you can get the number of items in a tuple by using the len() function. For example, if you have a tuple t = ("a", "b", "c"), then len(t) returns 312 An empty tuple is written as (), which means that you have to use an empty pair of parentheses to create a tuple with no items. For example, you can create an empty tuple t = () by using empty parentheses. However, if you want to create a tuple with only one item, you have to add a comma after the item, otherwise Python will not recognize it as a tuple. For example, you can create a tuple with one item t = ("a",) by using a comma12 Therefore, the correct answers are A. Tuples are immutable, which means that their contents cannot be changed during their lifetime. and D. Tuples can be indexed and sliced like lists. Reference: Python Tuples - W3SchoolsTuples in Python - GeeksforGeeks

• Question 22:

  Insert the correct snippet so that the program produces the expected output. Expected output:

  

  Code:

  

  A. b = 0 not in list

  B. b = list[0]

  C. b = 0 in list

  D. b = False

  Correct Answer: C

• Question 23:

  Assuming that the tuple is a correctly created tuple, the fact that tuples are immutable means that the following instruction:

  

  A. is illegal

  B. may be illegal if the tuple contains strings

  C. can be executed if and only if the tuple contains at least two elements

  D. is fully correct

  Correct Answer: A

• Question 24:

  What is the expected output of the following code?

  

  A. 2

  B. 4

  C. 5

  D. 3

  Correct Answer: B

• Question 25:

  What is the expected output of the following code?

  

  A. [1, 3]

  B. [1, 4]

  C. [4, 3]

  D. [1, 3, 4]

  Correct Answer: C

• Question 26:

  What is the expected output of the following code?

  

  A. ['Peter', 404, 3.03, 'Wellert', 33.3]

  B. None of the above.

  C. [404, 3.03]

  D. ['Peter', 'Wellert']

  Correct Answer: C

• Question 27:

  Take a look at the snippet, and choose the true statements: (Choose two.)

  

  A. nums is longer than vals

  B. nums and vals are of the same length

  C. vals is longer than nums

  D. nums and vals refer to the same list

  Correct Answer: BD

• Question 28:

  What is the output of the following snippet?

  

  A. 12

  B. (2, 1)

  C. (1, 2)

  D. 21

  Correct Answer: D

• Question 29:

  What is the expected output of the following code?

  print(list('hello'))

  A. hello

  B. [h, e, l, l, o]

  C. ['h', 'e', 'l', 'l', 'o']

  D. ['h' 'e' 'l' 'l' 'o']

  E. None of the above.

  Correct Answer: C

• Question 30:

  What will be the output of the following code snippet?

  

  A. [1, 3, 5, 7, 9]

  B. [8, 9]

  C. [1, 2, 3]

  D. [1, 2]

  Correct Answer: A