Python syntax is essential for writing clean and error-free programs. It provides structure and rules that must be followed when writing Python code, which allows the interpreter to understand the code. Having a clean and readable syntax is ultimately a reason for the popularity of Python among freshers and programmers with prior experience. A proper syntax is essential for writing efficient code, which makes it easier to debug. In this article, you will learn about the fundamental syntax rules of Python in detail with examples for each.
Table of Contents:
What is Syntax in Python?
Syntax in Python is a predefined set of rules that help in specifying how code has to be written and structured. Syntax includes indentation, keywords, variables, and statements, among other elements that help to make the code readable and executable. Without proper syntax, errors occur, and programming cannot be done in the most efficient manner. The correct syntax enables successful code execution as well as improved code organization. Understanding the syntax in Python is very important in writing clean and executable code.
Why is Syntax Important in Python?
The proper syntax in Python enables code execution and provides readability as a fundamental requirement. The following are some advantages of knowing Python syntax:
- Avoids Errors: The correct syntax helps to prevent errors that block the execution of the program.
- Easy to Read: Python includes a syntax with plain instructions that enables readers to understand code without any difficulty.
- Quick Debugging: As the code is well structured by following the syntax, it makes the debugging faster by quickly finding and fixing the errors.
- Works Everywhere: Proper syntax of Python makes sure that the code runs efficiently on different systems without any issues.
- Better Teamwork: Python provides a clean and consistent syntax, which makes it easy for others to understand the code and update it when required.
Python Syntax Rules and Structure
The structure and syntax rules in Python define how the code has to be written and executed. Python has a clean and readable syntax, with proper indentation and a line structure. The syntax rules must be followed to produce a program that works correctly. Now, we will look at Python’s line structure, multiline statements, indentation, and also the rules involved in using comments and whitespaces.
1. Case Sensitivity in Python
Python treats uppercase and lowercase letters differently. This means when we use the same variable names like Var and var, both are not treated as the same.
Example:
Output:
Explanation: Here, the Python syntax treats Intellipaat and intellipaat as two different variables because variable names in Python are case-sensitive.
2. Indentation in Python
Python uses indentation, like spaces or tabs, to define code blocks instead of {} like other programming languages. The loops, functions, and conditions in Python have to be properly indented.
Example:
Output:
Explanation: Here, the print() statement inside the function has to be indented. Python uses indentation to define code blocks, and if it is missing, it will raise an error.
3. Statements and Line Breaks in Python
Every statement in Python is typically typed on a new line, although several statements can be typed on a single line by following them with a semicolon (;), which helps in improving the readability.
Example:
Output:
Explanation: Here, the semicolon (;) allows writing multiple statements on the same line, but writing them on separate lines is mostly recommended, which helps in improving the readability of the code.
4. Multiline Statements in Python
If a statement is lengthy, you can place a backslash (\) at the end of the line to continue it, or use parentheses (()) to enclose it.
Example:
Output:
Explanation: Here, the backslash (\) allows breaking a long statement into multiple lines and maintains a correct syntax.
5. Whitespace Rules in Python
Python ignores the extra spaces except in the case of spacing during indentation, which leads to errors.
Some of the most important Whitespace rules are:
- Indentation: Python uses indentation instead of braces {} to define blocks of code, which is mandatory.
- Four spaces per indentation level: This is the standard practice in Python, which is used for better readability of the code.
- Inconsistent Indentation: There is no correct indentation such as adding an extra space leads to indentation Errors.
- Blank lines: It is necessary to add a blank line after the comment lines and the important logic of the code, which helps in improving the readability of the code and makes it look organized.
Example:
Output:
Explanation: Here, spaces before or after operators do not affect execution, but incorrect indentation will cause an error.
6. Keyword Usage in Python
Python has reserved words (keywords) that cannot be used as variable names because they are already defined and have a particular meaning that is used for performing a particular task.
Python has a set of reserved words (keywords) that cannot be used as identifiers. These words already have a predefined meaning and are case-sensitive.
| False |
class |
finally |
is |
return |
| None |
continue |
for |
lambda |
try |
| True |
def |
from |
non-local |
while |
| and |
del |
global |
not |
with |
| as |
el |
if |
or |
yield |
| assert |
else |
import |
pass |
async |
| break |
except |
in |
raise |
await |
Example:
Output:
Explanation: Here, class is a reserved keyword, so using it as a variable causes an error. Instead, a different name should be used.
7. Quotations in Python
Strings in Python are enclosed by single (‘), double (\”), or triple (”’ or “”) quotes.
Example:
Output:
Explanation: Here, Python allows using different types of quotation marks, but they must be paired correctly.
8. Variable Naming Rules
Python variable names must start with a letter or underscore (_) and cannot contain spaces or special characters except _.
Rules for naming a variable in Python:
- A variable name must start with a letter (A-Z or a-z) or an underscore (_).
- It cannot start with a number (0-9).
- Only letters, digits, and underscores (_) can be used in variable names.
- No spaces and special characters (@, $, %) are allowed.
- Python is case-sensitive (name and Name are different).
- Keywords like class, def, and return cannot be used as a variable name
Example:
Output:
Explanation: Here, variable names cannot contain special characters like ‘-‘, which leads to an error during execution, but _ is allowed as the first character.
9. Python Line Structure
Python code is composed of both physical and logical lines.
- Physical line: It is a sequence of characters that ends with the line itself. Unlike C and Java, Python does not require a semicolon to indicate the conclusion of a statement.
- Logical Line: A complete statement that may include one or more physical lines. Python can combine many physical lines to make a single logical line.
Example:
Output:
Explanation: Here, each print statement is written in a separate physical line, while the variable course_name combines multiple physical lines into a single line using a ‘\’ backslash.
Comments, Rules, and Syntax in Python
Comments in Python are used to add explanations within the code. It helps programmers to understand the complex logic and what is the use of the code in a particular place. Python provides different ways to write comments, which help in increasing the readability of the code.
Some important rules to be considered while writing Python code are:
- The # must be used for single-line comments. Everything that is written after the # in the same line is ignored.
- It is important to keep the comments short and clear.
- The multi-line comments must be used only in the places where it is necessary, and the triple quotes have to be used for the long explanations.
- Adding comments to the complex code is necessary, which helps in understanding the logic.
- The comments have to be updated regularly when the code is updated.
Python Single-Line Comment
A single-line comment starts with the # symbol. Everything after # on the same line is ignored by Python. It is usually used to give information about a single line of code.
Example:
Output:
Explanation: Here, the # symbol is used to add comments. The first comment describes the course assignment, while the second shows the printing of the course details, which consists of the name of the course along with the trainer’s name. These comments improve readability.
Python Multi-Line Comment
Python does not provide a particular syntax for multi-line comments, but multiple # symbols or triple quotes (”’ or “””) are used to write multi-line comments in Python.
Example:
Output: 
Explanation: Here, triple quotes (”’) are used to write a multi-line comment, which helps in explaining in detail the use of the code. This helps to understand the code easily.
String Formatting Syntax in Python
String formatting in Python helps to insert values inside a string in a structured way. Python provides different methods for formatting strings.
Syntax Rules:
- format(): Place {} as placeholders and use .format() to insert values.
Syntax: “{}”.format(value)
- f-string: It is used to insert variables inside {} directly.
Syntax: f”text {variable}”
- % operator: It is used to insert values based on format specifiers.
Syntax: “%format_specifier” % value
Example:
Output:
Explanation: Here, each method inserts values into strings differently. The format() method uses {} as placeholders, f-string directly places variables inside {}, and the % operator follows the old formatting style.
Escape Sequences Syntax in Python
Escape sequences in Python refer to special characters that are employed to format the text output, such as introducing a new line or tab space.
Syntax Rules:
- \n: It adds a new line inside a string.
Syntax: “text\ntext”
- \t: It inserts a tab space.
Syntax: “text\ttext”
- \\: It prints a single backslash.
Syntax: “C:\\path\\file”
- \’ and \”: It allows single or double quotes inside a string.
Syntax: ‘It\’s a good day’, “She said \”Hello\””
Example:
Output:
Explanation: Here, the escape sequences improve the structure of the output. \n adds a new line, \t creates spacing, \\ prints a backslash, and \” allows double quotes inside a string.
Operators and Expressions Syntax in Python
Python operators are symbols that act upon values. Python expressions are values, and operators are combined to produce results.
Syntax Rules:
- Arithmetic Operators: Used for mathematical calculations.
Syntax: a + b, a – b, a * b, a / b, a % b, a // b, a ** b
- Comparison Operators: It is used for comparing the values and returning True or False.
Syntax: a == b, a != b, a > b, a < b, a >= b, a <= b
- Logical Operators: It help in combining multiple conditions.
Syntax: a and b, a or b, not a
- Assignment Operators: It is used for assigning values and modifying variables.
Syntax: a = b, a += b, a -= b, a *= b, a /= b, a //= b, a **= b
- Bitwise Operators: It is used for performing bit-level operations.
Syntax: a & b, a | b, a ^ b, ~a, a << b, a >> b
Example:
Output:
Explanation: Here, each operator has a specific role. Arithmetic operators perform calculations, comparison operators verify conditions, logical operators assist in decision-making, and assignment operators change values.
Function Syntax in Python
Functions in Python are nothing but reusable blocks of code that are used to perform a specific task. They help in improving the organization of the code, along with the readability and reusability.
Defining a Function
The functions in Python are defined using the def keyword, which is then followed by a function name and optional parameters if required.
Syntax:
def function_name(parameters):
# Function body
return value
Calling a Function
A function is executed when it is called by its name, which is then followed by parentheses, passing arguments if there is any requirement.
Syntax:
function_name(arguments)
Example:
Output:
Explanation: Here, the greet function takes the name as an argument and returns a welcome message.
Conclusion
Python syntax does not utilize braces but rather uses indentation, which helps in increasing the readability of the code. Python does not use semicolons and is dynamically typed, so it is even easier for beginners. Knowing the syntax rules will help you write Python code that is more efficient with fewer errors. With a clear and simple syntax, Python allows developers to focus more on logic rather than syntax errors. Mastering these syntax rules is essential for writing a clean, efficient, error-free program.
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Python Syntax – FAQs
Frequently Asked Questions
Q1. What is Python syntax?
The syntax of Python is a collection of rules that describe the programming structures for writing your code in Python.
Q2. Why is indentation important in Python?
When you write your code in Python, indentation supports the definition of the outer code block, which is typically marked by curly braces in other languages.
Q3. How do you write a comment in Python?
A single-line comment in Python is initiated by using the hashtag symbol #, and multi-line comments may be initiated and ended with three quotation marks (“””) or three single quotation marks (”’).
Q4. What are Python identifiers?
Identifiers in Python refer to the names of your variables, functions, or classes. An identifier must start with a letter or underscore.
Q5. How do you print output in Python?
Use the print() command to output the result to the console, for example – print(“I hope you understood Python syntax. Keep practicing!”).
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