Python Tuples

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1. What is a Tuple?

• A tuple is an ordered, immutable (unchangeable) collection of elements.
• Tuples are defined using parentheses () or the tuple() constructor.
• Tuples can contain elements of different data types.

person = ("Raj", 25, "Chennai")

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2. Tuple Operations

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1. Accessing Elements

• Use indexing to access individual elements in a tuple.
• Python uses zero-based indexing (the first element has index 0).

person = ("Ram", 30, "Bangalore")
print(person[0])  # Output: Ram
print(person[-1])  # Output: Bangalore (negative indexing starts from the end)

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2. Slicing

• Extract a subtuple using a range of indices.
• Syntax: tuple[start:stop:step]

numbers = (1, 2, 3, 4, 5)
print(numbers[1:4])  # Output: (2, 3, 4) (from index 1 to 3)
print(numbers[::2])  # Output: (1, 3, 5) (every second element)

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3. Length

• Use len() to find the number of elements in a tuple.

fruits = ("apple", "banana", "cherry")
print(len(fruits))  # Output: 3

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4. Concatenation

• Combine two or more tuples using the + operator.

tuple1 = (1, 2, 3)
tuple2 = (4, 5, 6)
combined = tuple1 + tuple2
print(combined)  # Output: (1, 2, 3, 4, 5, 6)

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5. Repetition

• Repeat a tuple using the * operator.

numbers = (1, 2)
repeated = numbers * 3
print(repeated)  # Output: (1, 2, 1, 2, 1, 2)

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6. Checking for Elements

• Use the in keyword to check if an element exists in a tuple.

fruits = ("apple", "banana", "cherry")
print("banana" in fruits)  # Output: True
print("mango" in fruits)   # Output: False

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3. Tuple Methods

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1. count()

• Returns the number of times a specified value occurs in a tuple.

numbers = (1, 2, 3, 2, 4, 2)
print(numbers.count(2))  # Output: 3

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2. index()

• Returns the index of the first occurrence of a specified value.

fruits = ("apple", "banana", "cherry", "banana")
print(fruits.index("banana"))  # Output: 1

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4. Immutable Nature of Tuples

• Tuples are immutable, meaning their elements cannot be changed after creation.
• However, if a tuple contains mutable objects (e.g., lists), those objects can be modified.

person = ("Anand", 28, ["Chennai", "Bangalore"])
person[2].append("Mumbai")  # Modify the list inside the tuple
print(person)  # Output: ('Anand', 28, ['Chennai', 'Bangalore', 'Mumbai'])

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5. Unpacking Tuples

• Assign the elements of a tuple to variables in a single statement.

person = ("Bala", 35, "Delhi")
name, age, city = person
print(name)  # Output: Bala
print(age)   # Output: 35
print(city)  # Output: Delhi

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6. Nested Tuples

• A tuple can contain other tuples, creating a multi-level structure.

matrix = ((1, 2, 3), (4, 5, 6), (7, 8, 9))
print(matrix[1][2])  # Output: 6 (access element in the second row, third column)

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7. Additional Examples

• Creating a Tuple:
  person = ("Karthik", 40, "Hyderabad")
  print(person)  # Output: ('Karthik', 40, 'Hyderabad')
  
• Accessing Elements:
  name = person[0]
  print(name)  # Output: Karthik
  
• Slicing:
  numbers = (10, 20, 30, 40, 50)
  print(numbers[1:4])  # Output: (20, 30, 40)
  
• Unpacking:
  name, age, city = person
  print(city)  # Output: Hyderabad
  
• Checking for Elements:
  fruits = ("apple", "banana", "cherry")
  print("banana" in fruits)  # Output: True
  

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8. Best Practices

• Use tuples for collections of items that should not change (e.g., constants, configurations).
• Use parentheses for clarity, even when defining a single-element tuple (e.g., (1,)).
• Prefer tuples over lists for immutable data to ensure data integrity.