Data Types And Variables

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following are considered composite data types in Python?

  • Lists (correct)
  • Integers
  • Strings (correct)
  • Tuples (correct)
  • Dictionaries (correct)

Strings in Python are mutable, meaning their contents can be changed after creation.

False (B)

What is the primary difference between lists and tuples in Python regarding their mutability?

Lists are mutable, while tuples are immutable.

In a dictionary, a ______ is used to look up its associated value.

<p>key</p> Signup and view all the answers

Match the following Python functions with their corresponding actions:

<p>len() = Returns the number of characters in a string ord() = Returns the ordinal number of a character chr() = Returns the character corresponding to an ordinal number</p> Signup and view all the answers

What is the base most commonly used in computer science besides the decimal system?

<p>Base 2 (C)</p> Signup and view all the answers

To represent negative numbers, the one's complement is used.

<p>False (B)</p> Signup and view all the answers

Describe the process for converting a positive binary number to its negative two's complement representation.

<p>Invert all the bits, then increment the result by 1.</p> Signup and view all the answers

Which of the following is NOT a property of a variable in imperative programming languages?

<p>Velocity (B)</p> Signup and view all the answers

The NoneType data type has two possible values: True and False.

<p>False (B)</p> Signup and view all the answers

What operation returns the remainder of the division of two integers?

<p>modulo</p> Signup and view all the answers

The data type that represents integer numbers with a sign is called ______.

<p>int</p> Signup and view all the answers

Match the following boolean operators with their descriptions:

<p>and = True if and only if both operands are True or = True if and only if at least one operand is True not = Reverses the truth value of the operand</p> Signup and view all the answers

What is the result of dividing two integers using the / operator?

<p>A floating-point number (D)</p> Signup and view all the answers

It's possible to get the physical memory address of an object in Python using standard operations.

<p>False (B)</p> Signup and view all the answers

The operation that converts a floating-point number to an integer, removing digits after the decimal point is called ______ conversion.

<p>int</p> Signup and view all the answers

Flashcards

What is a variable?

A variable in Python is a name associated with an object in memory. It can hold different types of data, but its type is determined by the object it references.

What is the content of a variable?

The content of a variable is the specific object it points to. In Python, it's the actual data stored in the variable.

What is the size of a variable?

The size of a variable refers to the number of bytes used to store the object in memory.

What is the data type of a variable?

The data type of a variable tells us the kind of data it can store and what operations can be performed on that data.

Signup and view all the flashcards

What is the scope of a variable?

The scope of a variable defines the region of the program where it can be accessed. Variables are declared in Python when they are first assigned a value.

Signup and view all the flashcards

What is NoneType?

NoneType is a special data type in Python representing the absence of a value. Its only value is None.

Signup and view all the flashcards

What are Booleans?

Booleans (bool) represent truth values in logic - True or False. They are used for comparisons and conditional statements.

Signup and view all the flashcards

What are Integers?

Integers (int) are whole numbers, including positive, negative and zero. They are used for mathematical calculations.

Signup and view all the flashcards

What is a string?

A sequence of characters stored in a single variable, representing text data within a program.

Signup and view all the flashcards

How are strings represented?

In Python, strings are represented using single or double quotes.

  • "Hello"
  • 'World'
  • "Hello 'World'"
Signup and view all the flashcards

What does string concatenation mean?

A built-in function that combines two strings into one. It takes two strings as arguments and returns a new string that is the concatenation of the two.

Signup and view all the flashcards

How do you find the length of a string?

The function len() returns the number of characters in a string. Example: len("Hello") would return 5.

Signup and view all the flashcards

What is a list?

A list is a flexible data structure that holds an ordered sequence of items of different data types. It is mutable, meaning you can change its elements after it's created.

Signup and view all the flashcards

What is the difference between a list and a tuple?

Tuples are similar to lists, but they are immutable, meaning you can't change their elements once they are created. They are enclosed in parentheses ().

Signup and view all the flashcards

What is a dictionary?

A dictionary is a collection of key-value pairs. The key is used to access the associated value. It is a mutable data structure, meaning you can modify it after it is created.

Signup and view all the flashcards

How are numbers represented?

The most common number representation in Python. It's based on powers of 10, where each position represents a power of 10 (ones, tens, hundreds, etc.).

Signup and view all the flashcards

Study Notes

Data Types and Variables

  • Variables in Python are associated with objects in memory.
  • A variable is characterized by at least five properties: content, address, size, type, and scope.
  • Content: The specific object associated with the variable (binary sequence).
  • Address: The location of the object in memory (first byte address).
  • Size: The number of bytes used to describe the object.
  • Type: A collection of values of the same kind, indicating operations on the values. Python is dynamically typed, meaning the type of a variable can change over time.
  • Scope: The range of the program where the variable is usable.
    • Scope starts at the variable's declaration and lasts until the end of the block it's declared in (scope).
  • Note: In Python, it's difficult to get the exact object size.
  • Note: Python's data type and address can change over time.
  • Note: Python uses an interpreter, not a compiler so code needing integer values might not run properly if the value is larger than supported. This results in runtime errors.

Primitive Data Types

  • NoneType: Represents the absence of a result or value (one possible value).
  • Booleans: Represents truth values (True/False) using logical operations (and, or, not).
  • Integers: Represents whole numbers with a sign (positive or negative). Python integers can be arbitrarily large.
  • Floating-point numbers: Represent a subset of rational numbers stored in a special binary format, with potential precision issues.

Composite Data Types

  • Characters and Strings: Stores sequences of characters (Unicode). Operations include concatenation, finding length, and ordinal/character conversions.
  • Lists: Ordered, mutable collections of data objects of potentially different types. Using index notation (starting at 0) allows access to elements.
  • Tuples: Ordered, immutable collections of data objects of potentially different types, akin to lists with an immutable nature. Index notation similar to lists.
  • Dictionaries: Collections of key-value pairs where keys are unique. Keys can be any immutable type (integers, strings), while values can be any type. Access using square bracket notation that contains the key. The usage and structure of values and keys can be used in various ways for different tasks.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Data Types and Variables PDF

More Like This

Python Basic Concepts Quiz
13 questions

Python Basic Concepts Quiz

RespectableSodium avatar
RespectableSodium
Python Fundamental Concepts Quiz
10 questions

Python Fundamental Concepts Quiz

SnazzyUvarovite4013 avatar
SnazzyUvarovite4013
Python Variables and Data Types
19 questions

Python Variables and Data Types

SnappyAstronomy avatar
SnappyAstronomy
Data Types and Variables in Python
5 questions

Data Types and Variables in Python

BrightNewton avatar
BrightNewton
Use Quizgecko on...
Browser
Open
Browser
Browser