2. Syntax and Types

This chapter builds the basic vocabulary of Python programs: names, values, operators, and types.

• Variables and assignment

• Operators and expressions

• Basic scalar types

• Collection type overview

Chapter Video

This overview introduces numeric data, arithmetic operators, comparisons, and basic type conversion.

Python Tutorial for Beginners 3: Integers and Floats - Working with Numeric Data (11:55) by Corey Schafer

Hosted on YouTube; property of its original creator, embedded here for educational reference only.

Learning Objectives

By the end of this chapter, you will be able to:

1. Create and name variables using Python assignment syntax

2. Use arithmetic, comparison, logical, and assignment operators

3. Classify values by built-in type

4. Convert values between compatible built-in types

5. Choose appropriate basic and collection types for simple data

Chapter Flow

1. Variables and Objects

2. Python Operators

3. Built-in Types

Glossary

#	Term	Explanation
1	Variable	A name that refers to a value or object in a program.
2	Assignment statement	A statement that binds a variable name to a value, such as score = 95.
3	Naming Rules & Conventions	Shared rules and recommended styles for variable names and other identifiers.
4	Object	A Python value with an identity, a type, and data.
5	Identity	The unique object reference Python uses to tell whether two names point to the same object.
6	Alias	A second name that refers to the same object as another name.
7	Type	The category of a value, such as int, float, str, bool, list, or dict.
8	Operator	A symbol or word that performs an operation, such as +, ==, and, or, or in.
9	Operand	A value that an operator works on.
10	Expression	A piece of code that evaluates to a value.
11	Type conversion	The process of changing a value from one type to another.
12	Type hint	An annotation that records the expected type of a variable, parameter, or return value.
13	Mutable	Describes an object whose contents can be changed after creation.
14	Immutable	Describes an object whose contents cannot be changed after creation.
15	List	An ordered, mutable collection of values.
16	Tuple	An ordered, immutable collection of values.
17	Dictionary	A mutable collection that stores key-value pairs.
18	Set	A mutable collection that stores unique values without a fixed order.
19	Boolean	A type with two possible values: True and False.
20	Truthy	Describes a value that behaves like True in a Boolean context.
21	Falsy	Describes a value that behaves like False in a Boolean context.
22	Reassignment	Binding an existing variable name to a different object; the old object itself is not changed.
23	Mutation	Changing the contents of an object in place, such as appending to a list, so every name that refers to it sees the change.
24	Dynamic typing	Python’s approach of determining a variable’s type at run time from the value assigned, so you do not declare types.
25	Floor division	The // operator, which divides two numbers and rounds the result down to the nearest integer.
26	Modulus operator	The % operator, which returns the remainder after division.
27	Membership operator	The in or not in operator, which checks whether a value is present in a collection.
28	Short-circuit evaluation	Evaluation of and and or that stops as soon as the result is known, so the second operand may never be evaluated.
29	Operator precedence	The rules that decide which operations in an expression are evaluated first, such as ** before +.
30	Type casting	Explicit conversion that you perform by calling a type constructor, such as int("42").
31	Type coercion	Implicit conversion that Python performs automatically, such as treating 3 as 3.0 in 3 + 4.5.
32	String	An immutable sequence of characters written in quotes, such as "apple".
33	Concatenation	Joining strings end to end with the + operator.
34	Escape sequence	A backslash followed by a character, such as \n or \', that represents a special character inside a string.
35	Indexing	Accessing one item of a sequence by its position in square brackets, starting from 0, such as s[0].
36	Slicing	Extracting part of a sequence with [start:stop:step], where the item at the stop index is not included.

Chapter Overview Slides