Find close string matches for suggestions and typo recovery.
How It Works
difflib.get_close_matches(word, possibilities, n=3, cutoff=0.6) returns a ranked list of similar strings. Increase cutoff to reduce loose suggestions; fuzzy matching should not silently authorize a different account or operation.
Step-by-Step Example
import difflib
known_words = ['database', 'dashboard', 'developer']
print(difflib.get_close_matches('databse', known_words, n=2))Understanding the Example
- The expression "['database', 'dashboard', 'developer']" supplies the value stored as 'known_words'. This value is then used or checked by the later statements.
- The print() call exposes the result so you can compare it with the behavior described above. Check the value and its type when experimenting.
A successful run of this example prints the following output:
['database']Where This Fits in a Real Program
Start by writing down examples that should match and examples that must fail. Check whether you need to locate a substring, match a prefix or validate an entire field; these are different operations. Unicode and escape sequences can also change which characters are matched, so test accented text and empty input.
Practice: Try It Yourself
Adjust cutoff based on the cost of false matches.
For this exercise, predict the result before running the changed code. Then explain the difference between the original and modified cases using the actual values, not just whether the program completed.
Further Reading
Read the official Python documentation for complete parameters, return types and exceptions.
Common Beginner Mistakes
- Using fuzzy matches as exact identifiers in security-sensitive or billing operations.
- Suggest likely commands when a user mistypes a known option.
Key Takeaways
- Find close string matches for suggestions and typo recovery.
- difflib.get_close_matches(word, possibilities, n=3, cutoff=0.6) returns a ranked list of similar strings.
- Apply the demonstrated operation to the practice input and verify its result before depending on it in a larger program.