Strings are sequences of characters enclosed in quotes. Python provides powerful built-in functions and methods to manipulate strings efficiently.
1. Creating Strings
A string can be created using single, double, or triple quotes.
Example:
str1 = 'Hello'
str2 = "World"
str3 = '''Python is fun!'''
print(str1, str2, str3)
Output:
Hello World Python is fun!
2. Accessing Characters in a String
Strings are indexed, starting from 0.
Example:
text = "Python"
print(text[0]) # First character
print(text[-1]) # Last character
Output:
P
n
3. String Slicing
Extract a substring using slicing.
Syntax:
string[start:end:step]
Example:
text = "Hello, Python!"
print(text[0:5]) # Output: Hello
print(text[7:]) # Output: Python!
print(text[::-1]) # Output: !nohtyP ,olleH (Reversed String)
4. String Concatenation and Repetition
Example:
first = "Hello"
second = "World"
result = first + " " + second # Concatenation
print(result)
print(result * 3) # Repetition
Output:
Hello World
Hello WorldHello WorldHello World
5. String Methods
Python provides built-in methods to manipulate strings.
Example:
text = "python programming"
print(text.upper()) # Convert to uppercase
print(text.lower()) # Convert to lowercase
print(text.title()) # Convert to title case
print(text.replace("python", "Java")) # Replace words
print(text.strip()) # Remove leading/trailing spaces
6. Checking Substrings
Example:
text = "Learning Python is fun!"
print("Python" in text) # Output: True
print("Java" not in text) # Output: True
7. Splitting and Joining Strings
Example:
sentence = "Python is easy to learn"
words = sentence.split() # Split into words
print(words)
joined = "-".join(words) # Join words with '-'
print(joined)
Output:
['Python', 'is', 'easy', 'to', 'learn']
Python-is-easy-to-learn
8. String Formatting
Python provides multiple ways to format strings.
Using f-strings (Recommended)
name = "Alice"
age = 25
print(f"My name is {name} and I am {age} years old.")
Using format() method
print("My name is {} and I am {} years old.".format(name, age))
9. Escape Sequences
Escape sequences are used for special characters.
Example:
print("Hello\nWorld") # New line
print("She said \"Python is fun!\"") # Double quotes inside string
Summary
✅ Strings are sequences of characters enclosed in quotes.
✅ Indexing and slicing help access substrings.
✅ String methods allow modification, searching, and formatting.
✅ f-strings are the best way to format strings.
