extract_ngrams.py

import sys

def extract_ngrams(text: str, n: int = 2) -> list[str]:
    if n < 1 or n > len(text):
        print(f"Error: n should be within 1 and {len(text)}, instead it is: {n}")
        sys.exit(1)
        
    if n == 1:
        return list(text)

    return [text[i:i+n] for i in range(0, len(text) - n + 1)]

print(extract_ngrams("hello", n=2)) # => ["he", "el", "ll", "lo"]

print(extract_ngrams("hello", n=3)) # => ["hel", "ell", "llo"]