How do I deduplicate lists in Python with examples?

Deduplicating lists in Python can be easily accomplished using various methods. Below are some of the most common techniques to remove duplicates from a list while maintaining the order of elements.

# Method 1: Using a for loop
def deduplicate_list_with_loop(original_list):
    deduplicated_list = []
    for item in original_list:
        if item not in deduplicated_list:
            deduplicated_list.append(item)
    return deduplicated_list

# Example usage
original_list = [1, 2, 2, 3, 4, 4, 5]
print(deduplicate_list_with_loop(original_list))  # Output: [1, 2, 3, 4, 5]

# Method 2: Using set
def deduplicate_list_with_set(original_list):
    return list(set(original_list))

# Example usage
print(deduplicate_list_with_set(original_list))  # Output: [1, 2, 3, 4, 5]

# Method 3: Using dict.fromkeys() (maintains order in Python 3.7+)
def deduplicate_list_with_dict(original_list):
    return list(dict.fromkeys(original_list))

# Example usage
print(deduplicate_list_with_dict(original_list))  # Output: [1, 2, 3, 4, 5]