What is a String and its types in Python?

What is a String in Python?

In Python, a string is a sequence of characters enclosed within single quotes ('), double quotes ("), or triple quotes (''' or """).

Example:

string1 = 'Hello'
string2 = "World"
string3 = '''Python'''
string4 = """Programming"""

Types of String Formats in Python

Python provides various ways to format and manipulate strings:

1. String Concatenation

Joining multiple strings using the + operator.

name = "Alice"
greeting = "Hello, " + name + "!"
print(greeting)  # Output: Hello, Alice!

2. String Formatting Methods

a) Using % Formatting (Old Method)

This method is similar to C-style string formatting.

name = "Alice"
age = 25
print("Hello, %s! You are %d years old." % (name, age))
  • %s → String
  • %d → Integer
  • %f → Float

b) Using .format() Method

Introduced in Python 3, it allows inserting values in placeholders {}.

name = "Bob"
age = 30
print("Hello, {}! You are {} years old.".format(name, age))

You can also specify index positions:

print("Hello, {1}! You are {0} years old.".format(age, name))

c) Using f-Strings (Python 3.6+)

f-Strings (formatted string literals) are the most efficient way to format strings.

name = "Charlie"
age = 22
print(f"Hello, {name}! You are {age} years old.")

They support expressions inside {}:

num1, num2 = 10, 20
print(f"Sum of {num1} and {num2} is {num1 + num2}.")

3. Multi-line Strings

Using triple quotes (''' or """) for multi-line strings.

message = """Hello,
This is a multi-line string.
It spans multiple lines."""
print(message)

4. Raw Strings (r'' or r"")

Used to prevent escape characters (\n, \t, etc.) from being interpreted.

path = r"C:\Users\Alice\Documents\file.txt"
print(path)  # Output: C:\Users\Alice\Documents\file.txt

5. Byte Strings (b'')

Used for handling binary data.

byte_str = b"Hello"
print(byte_str)  # Output: b'Hello'

6. Unicode Strings

Python 3 strings are Unicode by default, but you can explicitly define them:

unicode_str = u"Hello, Unicode!"
print(unicode_str)

7. Escape Sequences in Strings

Escape sequences allow inserting special characters:

new_line = "Hello\nWorld"  # New line
tab_space = "Hello\tWorld"  # Tab space
quote_inside = "She said, \"Python is great!\""  # Double quotes inside string

8. String Methods

Python provides several built-in string methods:

s = " hello Python "

print(s.upper())     # ' HELLO PYTHON '
print(s.lower())     # ' hello python '
print(s.strip())     # 'hello Python' (removes spaces)
print(s.replace("Python", "World"))  # ' hello World '
print(s.split())     # ['hello', 'Python']

Conclusion

Python provides multiple ways to handle and format strings, from basic concatenation to f-strings and .format(). f-Strings (f"") are generally the most recommended due to their efficiency and readability.

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