Lære Text Preprocessing for Transformers | Preparing Data and Tokenization

Stryg for at vise menuen

When working with transformer models in natural language processing (NLP), the quality of your input data has a direct impact on model performance. Raw text often contains inconsistencies, such as mixed casing, unnecessary special characters, and irregular spacing, all of which can confuse the model and degrade results. Lowercasing text is a common step that helps reduce the vocabulary size and ensures that words like Apple and apple are treated the same, unless case carries meaning in your specific context. Removing special characters—such as stray punctuation or symbols—helps eliminate noise, while careful handling of whitespace ensures that token boundaries are clear and consistent. Each of these steps plays a critical role in making your data more uniform and easier for transformer models to process.

Note

Avoid aggressive preprocessing that removes context, such as stripping all punctuation. Some punctuation (like question marks or exclamation points) can carry important semantic information that transformers use to understand intent or meaning.


              12345678910111213141516171819
            
# List of sample sentences
sentences = [
    "Hello, World!   ",
    "Transformers are amazing...  ",
    "Fine-tune   your model: it's powerful!",
    "  Spaces    everywhere!   "
]

cleaned = []
for s in sentences:
    # Lowercase
    s = s.lower()
    # Remove special characters (keep only letters, numbers, and spaces)
    s = ''.join(c for c in s if c.isalnum() or c.isspace())
    # Collapse multiple spaces into one and strip leading/trailing spaces
    s = ' '.join(s.split())
    cleaned.append(s)

print(cleaned)

Note

Over-cleaning your text—such as removing all punctuation or stopwords—can strip away valuable context and negatively affect model performance. Always balance cleaning with preserving information relevant to your task.

Var alt klart?

Tak for dine kommentarer!

Sektion 2. Kapitel 1

Spørg AI

Spørg om hvad som helst eller prøv et af de foreslåede spørgsmål for at starte vores chat

Sektion 2. Kapitel 1