Python Syntax

Note

As a natural language like English or Ukrainian has its own rules to write down something, programming languages do. This makes them programming languages.

A programming language syntax is the set of rules and principles that govern how code is written and structured in a given programming language. Syntax encompasses the rules for writing statements, expressions, variables, data types, control structures, and other constructs that make up the language.

The syntax of a programming language defines how code is organized and interpreted by a compiler or interpreter. It defines the rules for writing valid statements and expressions that can be understood and executed by the language’s runtime system.

A programming language’s syntax is designed to be both readable and expressive, allowing programmers to write code that is easy to understand and modify. Syntax often influences the style and structure of code, as well as its maintainability and performance.

Different programming languages have different syntax, with some languages being more concise and expressive than others. While syntax is an important aspect of a programming language, it is only one of several factors that determine its ease of use, flexibility, and suitability for different programming tasks.

In the case of Python, the language’s syntax defines how code is written and structured in a way that is consistent, readable, and easy to understand. A general overview is provided below, no need to dive deep in this now. All of the following is to be discussed during the course. So, some of the key aspects of Python’s syntax include:

Indentation:

Python uses whitespace, specifically indentation, to delimit blocks of code, such as loops, conditionals, and functions. This means that the indentation level of a line determines which block of code it belongs to.

Statement structure:

Python statements are typically written on one line, with the end of the line indicating the end of the statement. However, if a statement is too long to fit on one line, it can be continued across multiple lines using backslashes.

Variables:

In Python, variables are created automatically when a value is assigned to them, and their type is inferred from the value. Variables can be assigned values of different types, including integers, floats, strings, and more complex data structures like lists and dictionaries.

Operators:

Python supports a wide range of operators for performing arithmetic, comparison, and logical operations. These include arithmetic operators like +, -, *, and /, as well as comparison operators like <, >, ==, and !=.

Control flow:

Python provides control flow statements like if, else, elif, for, and while to control the flow of execution in a program. These statements are used to make decisions, repeat code, or perform actions based on conditions.

Functions:

In Python, functions are defined using the def keyword and can take arguments and return values. The body of a function is defined using a block of indented code.

Modules:

Python has a large library of modules that provide pre-written code for a variety of tasks. Modules can be imported into a program using the import statement.

Exception handling:

Python provides a way to handle errors and exceptions in a program using the try, except, else, and finally keywords. These statements allow a program to gracefully recover from errors and continue executing.

In few words:

Input/Output example script

# This is a comment.
# It is used to provide additional information or context in a script.

# Getting input from the user
name = input("What is your name? ")  # stores string input by the user
age = int(input("How old are you? "))
is_student = input("Are you a student? (yes/no) ")

# Converting user input to boolean
is_student = is_student.lower() == "yes"

# Displaying values of variables
print("My name is", name)
print("I am", age, "years old")
print("I am a student:", is_student)

The code snippet above demonstrates some basics abilities of Python to gather data from the user, process it and print out back. Note the words starting with a # (hash) symbol. This is a comment. Any sequence of characters after the hash and till the line end are considered to be a comment. These are for those people, who see the code and they are ignored by the interpreter.

On the other hand each individual line is the instruction for the interpreter to perform some action, like gather inputs, do math, store data in memory etc.