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Hey everyone! Today we're going to explore one of the most commonly used data types in Python – strings. If you're just starting with Python or need a quick refresher, this guide will help you understand how strings work in Python. Let's get started!

Python Strings

  • A string in Python is a sequence of characters enclosed within single quotes, double quotes, or triple quotes.

  • Strings are immutable, meaning once created, they cannot be changed.

1. Defining a String​

Let's see how you can define a string in Python:

name = 'Python'                           # Define a string with single quotes  
greeting = "Hello, World!"               # Define a string with double quotes  
long_string = '''This is a long string    # Define a multi-line string with triple quotes  
that spans multiple lines.'''            # Continuing the multi-line string

2. Accessing Characters in a String​

You can access individual characters in a string using indexing:

name = 'Python'                           # Define a string  
first_char = name[0]                     # Access the first character: 'P'  
last_char = name[-1]                     # Access the last character: 'n'  
print(first_char)                        # Output: 'P'  
print(last_char)                         # Output: 'n'

3. Slicing a String​

You can slice a string to get a substring:

name = 'Python'                           # Define a string  
sub_str = name[0:3]                      # Slice from index 0 to 2: 'Pyt'  
print(sub_str)                           # Output: 'Pyt'

4. String Concatenation​

You can combine two or more strings using the + operator:

first_name = 'John'                       # Define a first name string  
last_name = 'Doe'                         # Define a last name string  
full_name = first_name + ' ' + last_name  # Concatenate strings with a space  
print(full_name)                         # Output: 'John Doe'

5. String Formatting​

You can format strings using f-strings, which is an efficient and readable way to include variables in a string:

name = 'Alice'                            # Define a name string  
age = 30                                  # Define an age variable  
message = f'{name} is {age} years old.'   # Format string with variables  
print(message)                           # Output: 'Alice is 30 years old.'

6. Common String Methods​

Python provides several built-in methods to work with strings. Here are a few commonly used ones:

text = '  Hello, Python!  '               # Define a string with leading and trailing spaces  
trimmed_text = text.strip()               # Remove leading and trailing spaces: 'Hello, Python!'  
uppercase_text = text.upper()             # Convert the string to uppercase: '  HELLO, PYTHON!  '  
lowercase_text = text.lower()             # Convert the string to lowercase: '  hello, python!  '  
replaced_text = text.replace('Python', 'World') # Replace 'Python' with 'World': '  Hello, World!  '  
print(trimmed_text)                      # Output: 'Hello, Python!'  
print(uppercase_text)                    # Output: '  HELLO, PYTHON!  '  
print(lowercase_text)                    # Output: '  hello, python!  '  
print(replaced_text)                     # Output: '  Hello, World!  '

7. String Length​

You can get the length of a string using the len() function:

text = 'Hello, Python!'                   # Define a string  
length = len(text)                       # Get the length of the string: 13  
print(length)                            # Output: 13