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Python Tuples

Tuples in Python are immutable sequences of arbitrary elements.

  •  defined by enclosing elements in parentheses (), separated by commas
  • e.g., my_tuple = (1, "a", 3.14)
  • often used in situations where an immutable sequence of data is needed
    • can be used as keys in dictionaries, which require immutability for hash mapping
  • have a smaller memory footprint compared to lists
    • more efficient for large datasets
# Define a tuple for a network device
network_device = ("192.168.1.1", "cisco", "admin", "password")
 
# Unpack the tuple
ip_address, device_type, username, password = network_device
 
# Use the unpacked values
print(f"Connecting to device {device_type} at {ip_address} using username {username}")

Tuple Length

Can determine the number of items contained in a tuple using the built-in len() function.

  • returns the number of elements in an iterable, including tuples

Tuples with Single Item

  • Create by placing a single value inside parentheses () followed with a comma ,
    • e.g., single_item_tuple = ("admin",)
  • trailing comma is necessary to distinguish the tuple from a simple parenthesized expression
  • useful for:
    • when a function is expected to return a tuple, but there is only one value to return, a single-item tuple can be used
      • ensures that the function’s return type is consistent

The Tuple Constructor

The tuple() constructor in Python is a built-in function that allows the creation of a tuple.

  • can take an iterable (like a list or a string) as an argument and convert it into a tuple
  • useful when there is a need to ensure the immutability of a sequence of data

Modifying Tuples

Accessing Item in a Tuple

  • access items using indexing
    • e.g., tuple[2]
  • ranges: tuple[start:stop]
  • negative indexes: tuple[-3:]
  • Check if an item exists in a tuple with in
    • 'item' in tuple
    • returns True or False

Updating Tuples

  • Tuples in Python are immutable
    • values cannot be changed once they are created
    • but there is a workaround:
      • convert the tuple into a list, changing the list, and then convert the list back into a tuple
# Define a tuple for a network device
network_device = ("192.168.1.1", "cisco", "admin", "password")
 
# Convert the tuple into a list
network_device_list = list(network_device)
 
# Change the IP address in the list
network_device_list[0] = "192.168.2.2"
 
# Convert the list back into a tuple
network_device = tuple(network_device_list)
 
# Print the new tuple
print(f"Network device: {network_device}")

Add Items to Tuple

  • items cannot be added directly
  • workaround:
    • concatenate the tuple with another tuple containing the new items
# Define a tuple for a network device
network_device = ("192.168.1.1", "cisco", "admin", "password")
 
# Define a new tuple with additional information
additional_info = ("port 22", "ssh")
 
# Concatenate the tuples
network_device = network_device + additional_info
 
# Print the new tuple
print(f"Network device: {network_device}")

Remove Item From Tuple

  • Cannot remove item directly
  • workaround:
    • convert the tuple to a list, removing the item, and then convert the list back to a tuple
# Original tuple with IP address, hostname, and model
device_info = ("192.168.1.1", "switch1", "Cisco 3750")
 
# Convert tuple to list
device_list = list(device_info)
 
# Remove old model from list
device_list.remove("Cisco 3750")
 
# Add new model to list
device_list.append("Cisco 3850")
 
# Convert list back to tuple
device_info = tuple(device_list)

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