Remove duplicates from a list.
Remove repeated hashable values while preserving the order in which they first appeared.
values = ["python", "bash", "python", "sql", "bash"]
unique = list(dict.fromkeys(values))
print(unique)Expected output EXAMPLE
['python', 'bash', 'sql']
Details
Uses only the Python standard library; no pip packages are required. See the verification record below for the exact Python version tested.
Items must be hashable, such as strings or numbers. Lists and dictionaries cannot be used as keys.
Tested on Ubuntu 24.04.5 LTS · · Python 3.12.3 · python3 3.12.3-0ubuntu2.1
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged) / C.UTF-8
- Interpreter invocation
python3 -c <published code>- Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd- Code SHA-256
c0b4b491430cbc786809202ecbbbddd70e45eaf8d6be748959e72097c6daecd1- Dependencies
- python3 3.12.3-0ubuntu2.1
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
# No input files required.
Observed standard output
['python', 'bash', 'sql']
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.