pydsa

Data structure and algorithm helpers for LeetCode-style Python: the functions one keeps rewriting at the top of a solution, written once and tested.

pip install pizza-lib   # the import name is pydsa

from pydsa import table, cells, nbrs, first_true, Multiset, maxheappush

dp = table(3, 4)                      # a 3 by 4 grid of zeros
for i, j in cells(grid):              # every cell, row by row
    for ni, nj in nbrs(grid, i, j):   # its on-grid neighbours
        ...
first_true(1, 10**9, lambda x: x * x >= n)   # the first x in [1, 10^9] with ok(x)

Modules

Every public name is importable from the package itself. The package imports only the standard library. The draw_* functions, tabulate-style output and viz_binary_search import rich, colorama, PrettyPrintTree and graphviz when first called:

pip install 'pizza-lib[draw]'

Every function has a docstring with its contract; the tests in tests/ are the examples.

Where it comes from

These helpers were the harness of the leet repo, preloaded into builtins for every solve there, and the library that the mu language pastes into the Python it emits. Both still use them from here.

Tests

pip install -e '.[test]'
pytest