lcpy gen resolves numbers and tags against the JSON catalog bundled with
your installed version. The error means the number, name, or tag is not in
that catalog. A close cousin, reported as a warning during bulk runs:
That one means the name does not match a catalog entry, most often because
the name is spelled as a slug instead of snake_case.
Reproduce
Fix
- Check what ships with your version: run
lcpy list, or lcpy list -t <tag> for one collection. Only listed problems can be generated.
- With
-s, spell the name exactly as the repo does, underscored:
two_sum, valid_palindrome. The hyphenated form (two-sum) is the
LeetCode URL slug and matches nothing. Numbers via -n sidestep
spelling entirely:
- Problem added to the repo after you installed: upgrade the package,
pip install --upgrade leetcode-py-sdk, then generate again.
- Problem not in the catalog at all: it has to be scraped and added
first; see Problem Creation.
Not this error? Every fix lives on
Troubleshooting. Last modified on August 31, 2026
