✨ Using Python to Manipulate Strings

Python provides powerful ways to manipulate strings, allowing us to perform a variety of operations on them. Let's explore how strings work in Python, including their creation, indexing, methods, and formatting.

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🌟 Creating Strings in Python

Strings in Python can be created using single quotes ('...'), double quotes ("..."), or triple quotes ('''...''' or """..."""). Triple quotes are particularly useful for creating multiline strings or docstrings.

📝 Examples:

# Using single quotes
str1 = 'Hello Python'
print(str1)  # Output: Hello Python

# Using double quotes
str2 = "Hello Python"
print(str2)  # Output: Hello Python

# Using triple quotes
str3 = '''Triple quotes are generally used for
multiline strings or docstrings.'''
print(str3)

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🌟 Strings Indexing and Splitting

Python strings are indexed starting from 0 for the first character. You can also use negative indices to access characters from the end of the string, starting with -1.

📝 Examples:

str = "HELLO"

# Positive indexing
print(str[0])  # Output: H
print(str[1])  # Output: E

# Negative indexing
print(str[-1])  # Output: O
print(str[-2])  # Output: L

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🌟 String Methods

Python provides a variety of built-in methods to work with strings. These methods do not modify the original string but return new strings based on the operations performed.

🛠️ Common String Methods:

• capitalize(): Converts the first character to uppercase.
• lower(): Converts the entire string to lowercase.
• upper(): Converts the entire string to uppercase.
• find(): Searches the string for a specified value and returns the position of where it was found.
• replace(): Returns a string where a specified value is replaced with another value.

📝 Examples:

str = "hello world"

# Capitalize the first letter
print(str.capitalize())  # Output: Hello world

# Convert to uppercase
print(str.upper())  # Output: HELLO WORLD

# Find a substring
print(str.find("world"))  # Output: 6

# Replace a substring
print(str.replace("world", "Python"))  # Output: hello Python

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🌟 String Indexing and Slicing

You can access individual characters or a range of characters in a string using indexing and slicing.

📝 Examples:

word = 'Didcoding'

# Accessing individual characters
print(word[0])  # Output: D
print(word[5])  # Output: d

# Slicing
print(word[0:2])  # Output: Di
print(word[2:5])  # Output: dco
print(word[::-1])  # Output: gnidcoDid (Reversed string)

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🌟 String Operators

Python supports various operators for string manipulation, including concatenation (+), repetition (*), and membership (in, not in).

📝 Examples:

str1 = "Hello"
str2 = " World"

# Concatenation
print(str1 + str2)  # Output: Hello World

# Repetition
print(str1 * 3)  # Output: HelloHelloHello

# Membership
print('H' in str1)  # Output: True

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🌟 String Formatting

Python offers several ways to format strings. The format() method and the % operator are two common approaches.

🛠️ Using format() Method:

name1 = "Hamza"
name2 = "Hashim"

# Using positional arguments
print("{} and {} are best friends.".format(name1, name2))  # Output: Hamza and Hashim are best friends.

# Using keyword arguments
print("{a} and {b} are best friends.".format(a="Hamza", b="Hashim"))  # Output: Hamza and Hashim are best friends.

🛠️ Using % Operator:

Integer = 10
Float = 1.29
String = "Hamza"

print("Integer: %d, Float: %f, String: %s" % (Integer, Float, String))
# Output: Integer: 10, Float: 1.290000, String: Hamza

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🌟 Escape Sequences in Strings

Escape sequences allow you to include special characters in strings, such as newline (\n), tab (\t), or backslash (\\).

🛠️ Common Escape Sequences:

Escape Sequence	Description	Example Code	Output/Effect
\n	Newline	print("Hello\nWorld")	Hello World
\t	Horizontal Tab	print("Hello\tWorld")	Hello World
\\	Backslash	print("This is a backslash: \\")	This is a backslash: \
\'	Single Quote	print('It\'s a sunny day!')	It's a sunny day!
\"	Double Quote	print("She said, \"Hello!\"")	She said, "Hello!"
\r	Carriage Return	print("Hello\rWorld")	World
\b	Backspace	print("Hello\bWorld")	HellWorld
\f	Form Feed	print("Hello\fWorld")	Hello (new page effect) World
\a	Bell (Alert)	print("Hello\aWorld")	Beep sound (if supported)
\v	Vertical Tab	print("Hello\vWorld")	Hello (vertical space) World
\0	Null Character	print("Hello\0World")	HelloWorld (null is invisible)
\N{name}	Unicode Character by Name	print("\N{Greek Capital Letter Omega}")	Ω
\uXXXX	Unicode Character with 16-bit hex value	print("\u03A9")	Ω (Greek Omega)
\UXXXXXXXX	Unicode Character with 32-bit hex value	print("\U0001F600")	😀 (Smiling Face Emoji)
\xXX	Character with the given hexadecimal value	print("\x48\x65\x6c\x6c\x6f")	Hello

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🌟 Escape Sequences in Strings

Escape sequences allow you to include special characters in strings, such as newline (\n), tab (\t), or backslash (\\). They are used with a backslash (\) followed by a character to represent special characters.

🛠️ Common Escape Sequences Examples:

1. \n - Newline
   Moves the text following it to a new line.

   print("Hello\nWorld")  # Output:
   # Hello
   # World

2. \t - Tab
   Adds a horizontal tab space.

   print("Hello\tWorld")  # Output: Hello   World

3. \\ - Backslash
   Represents a literal backslash character.

   print("This is a backslash: \\")  # Output: This is a backslash: \

4. \' - Single Quote
   Allows you to include a single quote inside a single-quoted string.

   print('It\'s a sunny day!')  # Output: It's a sunny day!

5. \" - Double Quote
   Allows you to include a double quote inside a double-quoted string.

   print("She said, \"Hello!\"")  # Output: She said, "Hello!"

6. \r - Carriage Return
   Moves the cursor to the beginning of the line. If any characters follow, they will overwrite the beginning characters.

   print("Hello\rWorld")  # Output: World

7. \b - Backspace
   Deletes the character before it (one step back).

   print("Hello\bWorld")  # Output: HellWorld

8. \f - Form Feed
   Moves the cursor to the next page (used mainly in printing).

   print("Hello\fWorld")  # Output: Hello (moves vertically to World on printers)

9. \a - Bell (Alert)
   Produces a beep sound in some systems.

   print("Hello\aWorld")  # Produces a beep sound (if the system supports it)

10. \v - Vertical Tab
    Moves the text to the next vertical tab position.

print("Hello\vWorld")  # Output: Hello (vertical space) World

11. \0 - Null Character
    Represents a null character in strings.

print("Hello\0World")  # Output: Hello World (null is invisible)

12. \N{name} - Unicode Character by Name
    Inserts a character by its Unicode name.

print("\N{Greek Capital Letter Omega}")  # Output: Ω

13. \uXXXX - Unicode (16-bit) Character
    Inserts a Unicode character with a 16-bit hex value.

print("\u03A9")  # Output: Ω (Greek Omega)

14. \UXXXXXXXX - Unicode (32-bit) Character
    Inserts a Unicode character with a 32-bit hex value.

print("\U0001F600")  # Output: 😀 (Smiling Face Emoji)

15. \xXX - Hexadecimal Character
    Inserts a character with the given hexadecimal value.

print("\x48\x65\x6c\x6c\x6f")  # Output: Hello

🌟 Raw Strings

Raw strings treat backslashes as literal characters, making them useful for regular expressions and file paths. You define a raw string by adding an r or R before the string.

📝 Example:

print(r"C:\Users\Hashim\Python")  # Output: C:\Users\Hashim\Python

In this example, the r prefix before the string tells Python to treat backslashes as literal characters instead of escape sequences.