You can create a string easily as shown below:
message1 = 'Hello Python'
message2 = "Welcome to Programming"
message3 = '''This is
a multi-line
string'''
String Slicing
Slicing allows you to extract a portion (substring) from a string using the syntax [start:end:step]. Python strings are indexed, meaning every character has a position number. The first character starts at index 0.text = "Python"
print(text[0]) # Output: P
print(text[1:4]) # Output: yth
print(text[:3]) # Output: Pyt
print(text[::2]) # Output: Pto
print(text[-1]) # Output: n
end → End index (excluded from result)
step → Optional step size (default is 1)
Negative indices can be used to access characters from the end of the string.
String Methods
Python provides numerous built-in string methods for text manipulation. These methods do not modify the original string; instead, they return a new one.| Method | Description | Example |
|---|---|---|
| upper() | Converts all characters to uppercase | "python".upper() → "PYTHON" |
| lower() | Converts all characters to lowercase | "PYTHON".lower() → "python" |
| title() | Capitalizes the first letter of each word | "hello world".title() → "Hello World" |
| capitalize() | Capitalizes the first character | "python".capitalize() → "Python" |
| strip() | Removes leading and trailing spaces | " hello ".strip() → "hello" |
| replace() | Replaces a substring with another | "I like Java".replace("Java", "Python") → "I like Python" |
| split() | Splits the string into a list | "a,b,c".split(",") → ['a', 'b', 'c'] |
| join() | Joins elements of a list into one string | " ".join(['I', 'love', 'Python']) → "I love Python" |
| find() | Returns index of a substring (-1 if not found) | "Python".find("th") → 2 |
| count() | Counts occurrences of a substring | "banana".count("a") → 3 |
String Immutability
Strings in Python are immutable, meaning their content cannot be changed after creation. If you try to modify a string, Python will throw an error.text = "Python"
text[0] = "J" # Error
new_text = "J" + text[1:]
print(new_text) # Output: Jython
Escape Sequences
Escape sequences allow you to include special characters or formatting inside strings. They start with a backslash ().| Escape Sequence | Meaning | Example Output |
|---|---|---|
| \n | New line | "Hello\nWorld" → Hello World |
| \t | Tab space | "Python\tLanguage" → Python Language |
| \\ | Backslash | "C:\\path\\file.txt" → C:\path\file.txt |
| \' | Single quote | 'It\'s Python' → It's Python |
| \" | Double quote | "He said \"Hi\"" → He said "Hi" |
String Formatting
Python provides multiple ways to format strings dynamically — i.e., insert variables or expressions into strings.1. f-strings (Python 3.6+)
This is the most modern and efficient way to format strings.name = "Alice"
age = 25
print(f"My name is {name} and I am {age} years old.")
print(f"Next year, I will be {age + 1} years old.")
2. format() Method
name = "Alice"
age = 25
print("My name is {} and I am {} years old.".format(name, age))
print("My name is {0} and I am {1}.".format(name, age))
3. % Formatting (Older style)
name = "Alice"
age = 25
print("My name is %s and I am %d years old." % (name, age))
Summary
Strings are the foundation of text processing in Python. Understanding how to manipulate and format them effectively will make your programs more readable, dynamic, and user-friendly.| Concept | Description |
|---|---|
| String | Sequence of characters enclosed in quotes |
| Slicing | Extracts specific portions of a string |
| String Methods | Built-in functions for text manipulation |
| Immutability | Strings cannot be changed once created |
| Escape Sequences | Used to include special characters like \n and \t |
| String Formatting | Combines variables and text dynamically |