Files
MCM-ICM_Toolkit/tests/test_data.py
T
guzhujushi 6758e81c9d fix(data): 校验早于副作用,补空行;经验写入 pitfalls
save_table 的两处收尾(用户授权代改):

- 后缀校验原先藏在 if/else 分支的 else 里,排在 path.parent.mkdir(...) 之后,
  传 sub/x.txt 会先把 sub\ 建出来再抛 ValueError。改成守卫子句,集中在 mkdir 之前,
  校验段结束后才产生副作用;此时 else 分支自然消失,用回 if/else 两路分派
- __all__ 与下一个 def 之间补回第二个空行(PEP 8 / E302)

测试:
- 新增 test_save_table_validates_before_touching_disk,
  断言参数非法时 tmp_path 下一个条目都不留(ValueError 与 TypeError 两条路径)
- 40 passed / 44 skipped,两套环境一致;ruff All checks passed

文档:
- docs/dev/personal-pitfalls.md 追加条目 5(参数校验排在副作用之后)
  与条目 6(把 lint 的"没报错"当成"没问题"),索引表同步加行
- STATUS:io.py 收尾,L0 第 3 项完成;测试计数 40
- CHANGELOG:Fixed 段补两条
2026-10-01 23:26:47 +08:00

173 lines
5.7 KiB
Python

"""data 包测试。
L0 阶段的约定:**只测已实现的行为**。未实现的算法用逐条 skip 标出,
不要用模块级 pytestmark —— 那会把同文件里已实现的函数一起跳过,
让 load_table 这种已经写好的函数变成零覆盖。
"""
from __future__ import annotations
from pathlib import Path
import numpy as np
import pandas as pd
import pytest
_NOT_IMPLEMENTED = "未实现:见 docs/03-roadmap.md L0/L1"
# ---------------------------------------------------------------- io: load_table
def test_load_table_detects_gbk(tmp_path):
"""国内赛题数据常见 GBK,编码探测必须能兜住。"""
from mcm_toolkit.data import load_table
p = tmp_path / "gbk.csv"
p.write_bytes("城市,人口\n北京,2189\n".encode("gbk"))
df = load_table(p)
assert list(df.columns) == ["城市", "人口"]
def test_load_table_keeps_utf8_readable(tmp_path):
"""UTF-8 文件必须按 UTF-8 读出,不能先试 GBK 变成乱码。"""
from mcm_toolkit.data import load_table
p = tmp_path / "utf8.csv"
p.write_text("省份,GDP增速\n广东,5.8\n", encoding="utf-8")
df = load_table(p)
assert list(df.columns) == ["省份", "GDP增速"]
assert df.loc[0, "省份"] == "广东"
def test_load_table_maps_na_like_tokens_to_nan(tmp_path):
"""赛题里的缺失值长得五花八门,默认 na_values 要全部吃成 NaN。"""
from mcm_toolkit.data import load_table
p = tmp_path / "na.csv"
p.write_text("a,b,c\n1,NA,\n2,-,#N/A\n", encoding="utf-8")
df = load_table(p)
assert df["b"].isna().all()
assert df["c"].isna().all()
assert df["a"].notna().all()
def test_load_table_respects_explicit_encoding(tmp_path):
"""显式给了 encoding 就照办,不再做探测。"""
from mcm_toolkit.data import load_table
p = tmp_path / "gbk.csv"
p.write_bytes("城市,人口\n上海,2487\n".encode("gbk"))
df = load_table(p, encoding="gbk")
assert list(df.columns) == ["城市", "人口"]
def test_load_table_rejects_unknown_suffix(tmp_path):
"""不支持的扩展名要抛 ValueError,而且要带上后缀名。"""
from mcm_toolkit.data import load_table
p = tmp_path / "data.txt"
p.write_text("a,b\n1,2\n", encoding="utf-8")
with pytest.raises(ValueError, match=r"\.txt"):
load_table(p)
def test_load_table_missing_file_raises(tmp_path):
"""文件不存在时要把路径原样带出来,方便定位。"""
from mcm_toolkit.data import load_table
missing = tmp_path / "nope.csv"
with pytest.raises(FileNotFoundError, match=r"nope\.csv"):
load_table(missing)
# ---------------------------------------------------------------- io: save_table
def test_save_table_round_trip(tmp_path):
"""存进去再读出来,内容要一致,并且返回实际写入的 Path。"""
from mcm_toolkit.data import load_table, save_table
df = pd.DataFrame({"城市": ["北京", "上海"], "人口": [2189.0, 2487.0]})
out = save_table(df, tmp_path / "out.csv")
assert isinstance(out, Path)
assert out.exists()
back = load_table(out)
assert list(back.columns) == ["城市", "人口"]
assert back["人口"].tolist() == [2189.0, 2487.0]
def test_save_table_rejects_non_dataframe(tmp_path):
"""传错类型要当场报错,不要写出一个奇怪的文件。"""
from mcm_toolkit.data import save_table
with pytest.raises(TypeError):
save_table([1, 2, 3], tmp_path / "bad.csv")
def test_save_table_validates_before_touching_disk(tmp_path):
"""校验必须早于副作用:参数不合法时,一个目录、一个文件都不能留下。"""
from mcm_toolkit.data import save_table
with pytest.raises(ValueError, match=r"\.txt"):
save_table(pd.DataFrame({"a": [1]}), tmp_path / "d1" / "x.txt")
with pytest.raises(TypeError):
save_table([1, 2, 3], tmp_path / "d2" / "x.csv")
assert sorted(p.name for p in tmp_path.iterdir()) == []
# ------------------------------------------------- 以下为未实现算法(L0/L1 待写)
@pytest.mark.skip(reason=_NOT_IMPLEMENTED)
def test_detect_outliers_finds_planted_points():
"""人工埋 3 个离群点,IQR 法应正好命中 3 个。"""
from mcm_toolkit.data import detect_outliers
x = np.concatenate([np.arange(100.0), [1e6, -1e6, 1e7]])
mask = np.asarray(detect_outliers(x, method="iqr"))
assert mask.sum() == 3
assert mask[-3:].all()
@pytest.mark.skip(reason=_NOT_IMPLEMENTED)
def test_detect_outliers_returns_mask_not_filtered_data():
"""约定:只标不删——返回与原数据同形的布尔掩码。"""
from mcm_toolkit.data import detect_outliers
x = np.arange(50.0)
mask = np.asarray(detect_outliers(x, method="zscore"))
assert mask.shape == x.shape
assert mask.dtype == bool
@pytest.mark.skip(reason=_NOT_IMPLEMENTED)
def test_normalize_minmax_range(rng):
from mcm_toolkit.data import normalize
x = rng.normal(size=(50, 3))
out = np.asarray(normalize(x, method="minmax"))
assert np.allclose(out.min(axis=0), 0.0)
assert np.allclose(out.max(axis=0), 1.0)
@pytest.mark.skip(reason=_NOT_IMPLEMENTED)
def test_standardize_has_zero_mean_unit_std(rng):
from mcm_toolkit.data import standardize
x = rng.normal(5, 3, size=1000)
out = np.asarray(standardize(x))
assert abs(out.mean()) < 1e-9
assert abs(out.std() - 1.0) < 1e-9
@pytest.mark.skip(reason=_NOT_IMPLEMENTED)
def test_train_test_split_sizes_and_no_overlap(rng):
from mcm_toolkit.data import train_test_split
X = rng.normal(size=(100, 2))
Xtr, Xte = train_test_split(X, test_size=0.2, random_state=0)
assert len(Xtr) == 80 and len(Xte) == 20
assert len({tuple(r) for r in Xtr} & {tuple(r) for r in Xte}) == 0