In Python, literals are used to represent fixed values that are assigned to variables or used directly in expressions. There are several types of literals in Python, including:
- Numeric literals: Numeric literals represent numerical values. They can be integers, floating-point numbers, or complex numbers. Examples include 42, 3.14, and 2+3j.
- String literals: String literals represent strings of characters enclosed in quotes. They can be enclosed in either single quotes (‘…’) or double quotes (“…”). Examples include ‘Hello, world!’, “Python is great!”, and ’42’.
- Boolean literals: Boolean literals represent the two Boolean values True and False. They are used to represent logical values in expressions. Examples include True and False.
- None literal: The None literal is used to represent a null or empty value. It is often used to indicate the absence of a value or as a placeholder until a value is assigned. Example includes None.
- Literal Collections:
- List literals: List literals represent ordered collections of values, enclosed in square brackets and separated by commas. Example: [1, 2, 3, 4].
- Tuple literals: Tuple literals are similar to list literals, but they are enclosed in parentheses instead of square brackets. Example: (1, 2, 3, 4).
- Set literals: Set literals represent unordered collections of unique values, enclosed in curly braces and separated by commas. Example: {1, 2, 3, 4}.
- Dictionary literals: Dictionary literals represent key-value pairs, enclosed in curly braces and separated by colons and commas. Example: {‘name’: ‘John’, ‘age’: 30}.
These literals can be used in Python programs as values for variables, as function arguments, or in expressions.
Types of String Literals:
In Python, there are two types of string literals:
- Single-quoted string literals: Single-quoted string literals are enclosed in single quotes (‘…’). They can contain any character except a single quote, which must be escaped using a backslash (‘). For example:
my_string = 'This is a single-quoted string literal.'
- Double-quoted string literals: Double-quoted string literals are enclosed in double quotes (“…”). They can contain any character except a double quote, which must be escaped using a backslash (“). For example:
my_string = "This is a double-quoted string literal."
Both single-quoted and double-quoted string literals are equivalent in Python, and you can use whichever one you prefer. However, it’s a good practice to be consistent within your codebase and choose one style over the other.
In addition to these basic string literals, there are also other types of string literals in Python:
- Triple-quoted string literals: Triple-quoted string literals are enclosed in triple quotes (either ”’…”’ or “””…”””). They can span multiple lines and can contain any character, including single quotes and double quotes, without the need for escaping. They are often used for docstrings (documentation strings) or for writing long strings that span multiple lines. For example:
my_string = '''This is a triple-quoted string literal that spans multiple lines.'''
- Raw string literals: Raw string literals are prefixed with an ‘r’ character, which indicates that backslashes should be treated as literal backslashes rather than escape characters. They are often used for regular expressions or file paths, where backslashes are commonly used as separators. For example:
my_string = r'C:\Users\John\Documents\file.txt'
These are the types of string literals in Python that you can use to create strings in your programs.