Files
datatools-dev/src/gui/pages/4_Missing_Values.py
Michael 904356f4e8 feat(gui): inline Help popover next to every tool's title
Adds a contextual Help button on each detail page, right of the title.
Clicking it opens a Streamlit popover with a one-shot how-to: when to
use, numbered steps, before→after examples, and an optional one-line
tip. Designed to be scannable — no paragraph prose.

Implementation:
- New ``render_tool_header(tool_id)`` helper in components replaces the
  bare ``st.title(...) + st.caption(...)`` block on each of the 11 tool
  pages. Title in the wide column, popover in a narrow right column;
  caption sits on its own line beneath.
- Help content is one markdown blob per tool stored in i18n under
  ``tools.<id>.help_md`` (en + es). Editors can tweak copy without
  touching Python.
- ``help.button_label`` and ``help.missing_body`` keys added to both
  packs for the popover trigger and the empty-tool fallback.

All 11 tool pages now use the same header pattern — including the
PDF Extractor and Reconciler which previously had hardcoded title/
caption pairs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-06-02 17:21:55 +00:00

446 lines
16 KiB
Python

"""DataTools Fix Missing Values — Streamlit page."""
from __future__ import annotations
import io
import json
import sys
from pathlib import Path
import pandas as pd
import streamlit as st
_project_root = Path(__file__).resolve().parent.parent.parent.parent
if str(_project_root) not in sys.path:
sys.path.insert(0, str(_project_root))
from src.gui.components import (
back_to_home_link,
render_sticky_footer,
render_tool_header,
hide_streamlit_chrome,
html_download_button,
pickup_or_upload,
require_feature_or_render_upgrade,
)
from src.i18n import t
from src.core.missing import (
DEFAULT_SENTINELS,
MissingOptions,
PRESETS,
handle_missing,
profile_missing,
)
from src.license import FeatureFlag
hide_streamlit_chrome()
render_sticky_footer()
back_to_home_link()
from src.audit import log_page_open
log_page_open("4_Missing_Values")
require_feature_or_render_upgrade(FeatureFlag.MISSING_HANDLER)
# ---------------------------------------------------------------------------
# Header
# ---------------------------------------------------------------------------
render_tool_header("04_missing_handler")
# ---------------------------------------------------------------------------
# File upload
# ---------------------------------------------------------------------------
uploaded = pickup_or_upload(
label="Import CSV or Excel file",
key="missing_file_upload",
types=["csv", "tsv", "xlsx", "xls"],
)
if uploaded is None:
st.info("Import a CSV, TSV, or Excel file to begin.")
st.stop()
@st.cache_data(show_spinner=False)
def _read_uploaded(name: str, data: bytes) -> pd.DataFrame:
"""Read the uploaded bytes into a DataFrame.
Unlike the text cleaner, we do *not* force ``dtype=str`` here: missing-
value handling is more useful when numeric columns are typed correctly
(so mean / median / interpolate work without manual coercion).
Sentinel strings are still detected because they survive in object
columns where any cell is non-numeric.
"""
suffix = Path(name).suffix.lower()
bio = io.BytesIO(data)
if suffix in (".xlsx", ".xls"):
return pd.read_excel(bio)
for enc in ("utf-8", "utf-8-sig", "latin-1"):
try:
bio.seek(0)
sep = "\t" if suffix == ".tsv" else ","
return pd.read_csv(bio, encoding=enc, sep=sep, on_bad_lines="warn")
except UnicodeDecodeError:
continue
bio.seek(0)
return pd.read_csv(bio, encoding="latin-1")
try:
df = _read_uploaded(uploaded.name, uploaded.getvalue())
except Exception as e:
from src.core.errors import format_for_user
st.error(
f"**Could not read `{uploaded.name}`**\n\n"
f"```\n{format_for_user(e)}\n```"
)
st.stop()
# Collapse the input preview + options once the user has clicked
# Handle Missing Values so the Results section below is the primary
# visual focus. The user can re-expand to re-inspect the source rows
# or tweak strategy and rerun.
_has_result = st.session_state.get("missing_result") is not None
with st.expander(f"Preview: {uploaded.name}", expanded=not _has_result):
st.caption(f"{len(df)} rows, {len(df.columns)} columns")
st.dataframe(df.head(10), width="stretch")
st.divider()
# ---------------------------------------------------------------------------
# Options (Missingness profile + Strategy)
# ---------------------------------------------------------------------------
#
# Wrapped in an outer expander whose default state mirrors the preview
# expander above: open before a result exists, folded once the user has
# clicked Handle Missing Values. The Missingness profile lives inside
# this expander too — after a run the Results section shows a richer
# before-vs-after comparison that supersedes the static input profile,
# so keeping it tucked away with the controls cleanly pushes Results
# to the top of the visible area.
with st.expander("Options", expanded=not _has_result):
st.subheader("Missingness profile")
initial_profile = profile_missing(df, MissingOptions())
prof_df = initial_profile.to_dataframe()
m1, m2, m3, m4 = st.columns(4)
m1.metric("Rows", initial_profile.rows_total)
m2.metric("Cells missing", initial_profile.cells_missing)
m3.metric("% cells missing", f"{initial_profile.cells_missing_pct:.1f}%")
m4.metric("Complete rows", initial_profile.rows_complete)
st.dataframe(prof_df, width="stretch", hide_index=True)
if initial_profile.cells_missing == 0:
st.success("No missing values or disguised nulls detected. Nothing to handle.")
st.divider()
st.subheader("Strategy")
preset_label = st.radio(
"Preset",
[
"detect-only (standardize sentinels to NaN, no fill or drop)",
"safe-fill (numeric → median, categorical → mode)",
"drop-incomplete (drop any row with missing)",
],
index=0,
help=(
"detect-only: replace 'N/A', '-', 'NULL', etc. with real NaN, then stop. "
"safe-fill: also fill — numeric columns with median, others with mode. "
"drop-incomplete: also drop every row that has any missing cell."
),
)
preset_key = preset_label.split(" ", 1)[0]
options = MissingOptions.from_preset(preset_key)
with st.expander("Advanced options"):
col_a, col_b = st.columns(2)
with col_a:
st.markdown("**Detection**")
options.standardize_sentinels = st.checkbox(
"Standardize disguised nulls to NaN",
value=options.standardize_sentinels,
help="Replace 'N/A', '-', 'NULL', whitespace-only cells, etc. with real NaN.",
)
sentinels_text = st.text_input(
"Sentinel values (comma-separated)",
value=", ".join(options.sentinels),
disabled=not options.standardize_sentinels,
help="Matched case-insensitively after stripping whitespace.",
)
options.sentinels = [
s.strip() for s in sentinels_text.split(",") if s.strip()
]
with col_b:
st.markdown("**Strategy override**")
strat_options = [
"(use preset)",
"none", "drop_row", "drop_col", "drop_both",
"mean", "median", "mode", "constant",
"ffill", "bfill", "interpolate",
]
strat_choice = st.selectbox(
"Global strategy",
strat_options,
index=0,
help=(
"drop_row / drop_col use the thresholds below. "
"mean / median / interpolate are numeric only — non-numeric "
"columns fall back to the categorical strategy."
),
)
if strat_choice != "(use preset)":
options.strategy = strat_choice # type: ignore[assignment]
cat_strat = st.selectbox(
"Categorical fallback (for non-numeric columns)",
["mode", "constant", "ffill", "bfill", "none"],
index=0,
)
options.categorical_strategy = cat_strat # type: ignore[assignment]
if options.strategy == "constant" or cat_strat == "constant":
fill_val = st.text_input(
"Constant fill value",
value="",
help="Used when strategy = constant. Leave blank to fill with empty string.",
)
options.fill_value = fill_val
st.markdown("**Drop thresholds**")
col_c, col_d = st.columns(2)
with col_c:
options.row_drop_threshold = st.slider(
"Row drop threshold (drop rows with ≥ this fraction missing across selected cols)",
0.0, 1.0, options.row_drop_threshold, 0.05,
)
with col_d:
options.col_drop_threshold = st.slider(
"Column drop threshold (drop columns with ≥ this fraction missing)",
0.0, 1.0, options.col_drop_threshold, 0.05,
)
st.markdown("**Scope**")
selected_cols = st.multiselect(
"Columns to handle (default: all)",
options=list(df.columns),
default=list(df.columns),
)
skip_cols = st.multiselect(
"Columns to skip",
options=list(df.columns),
default=[],
)
options.columns = selected_cols if selected_cols else None
options.skip_columns = list(skip_cols)
st.markdown("**Per-column strategy overrides** (optional)")
st.caption(
"Set a different strategy for specific columns. Leave any row blank to "
"use the global strategy."
)
per_col_overrides: dict[str, str] = {}
only_missing_cols = [
r.column for r in initial_profile.columns if r.has_missing
]
if only_missing_cols:
edit_df = pd.DataFrame({
"column": only_missing_cols,
"strategy": ["" for _ in only_missing_cols],
})
edited = st.data_editor(
edit_df,
width="stretch",
hide_index=True,
column_config={
"column": st.column_config.TextColumn("Column", disabled=True),
"strategy": st.column_config.SelectboxColumn(
"Override",
options=[
"", "drop_row", "drop_col",
"mean", "median", "mode", "constant",
"ffill", "bfill", "interpolate",
],
),
},
key="missing_per_col_editor",
)
for _, row in edited.iterrows():
if row["strategy"]:
per_col_overrides[row["column"]] = row["strategy"]
options.column_strategies = per_col_overrides # type: ignore[assignment]
# ---------------------------------------------------------------------------
# Run
# ---------------------------------------------------------------------------
st.divider()
if st.button("Handle Missing Values", type="primary", width="stretch"):
with st.spinner("Handling..."):
try:
result = handle_missing(df, options)
except (ValueError, OSError) as e:
from src.core.errors import format_for_user
st.error(format_for_user(e))
st.stop()
st.session_state["missing_result"] = result
from src.audit import log_event
log_event("tool_run", "Fix Missing Values run", page="4_Missing_Values")
st.session_state["missing_input_name"] = uploaded.name
st.session_state["missing_options"] = options.to_dict()
# One-shot flag picked up on the next pass to scroll the parent
# document to the Results anchor (see scroll snippet below).
st.session_state["_missing_scroll_to_results"] = True
# Force a second rerun so the preview and options expanders see
# the new result on the NEXT script pass and collapse themselves.
# Without this they stay expanded until the user touches any
# other widget.
st.rerun()
result = st.session_state.get("missing_result")
if result is None:
st.info("Choose a strategy and click **Handle Missing Values** to run.")
st.stop()
# ---------------------------------------------------------------------------
# Results
# ---------------------------------------------------------------------------
# Anchor target for the auto-scroll snippet at the end of this block.
# A bare ``<div id="...">`` survives Streamlit's HTML sanitizer (only
# ``<script>`` is stripped), and a 1px-tall div doesn't visually shift
# anything. Placed before the subheader so the scrolled-to viewport
# starts a few pixels above the section heading rather than below it.
st.markdown(
'<div id="missing-results-anchor" style="height:1px"></div>',
unsafe_allow_html=True,
)
st.subheader("Results")
m1, m2, m3, m4 = st.columns(4)
m1.metric("Sentinels → NaN", result.sentinels_standardized)
m2.metric("Cells filled", result.cells_filled)
m3.metric("Rows dropped", result.rows_dropped)
m4.metric("Columns dropped", len(result.columns_dropped))
if result.columns_dropped:
st.warning(f"Dropped columns: {', '.join(result.columns_dropped)}")
st.markdown("**Missingness — before vs. after**")
before = result.profile_before.to_dataframe().set_index("column")[
["missing", "missing_pct"]
].rename(columns={"missing": "before_missing", "missing_pct": "before_pct"})
after = result.profile_after.to_dataframe().set_index("column")[
["missing", "missing_pct"]
].rename(columns={"missing": "after_missing", "missing_pct": "after_pct"})
combined = before.join(after, how="outer").fillna(0)
st.dataframe(combined, width="stretch")
if result.strategy_per_column:
st.markdown("**Strategy applied per column**")
strat_df = pd.DataFrame(
[{"column": c, "strategy": s} for c, s in result.strategy_per_column.items()]
)
st.dataframe(strat_df, width="stretch", hide_index=True)
if not result.changes.empty:
st.markdown("**Audit (first 50 changes)**")
audit_view = result.changes.head(50).copy()
audit_view["row"] = audit_view["row"].apply(lambda x: "" if x == -1 else x + 1)
st.dataframe(audit_view, width="stretch", hide_index=True)
if len(result.changes) > 50:
st.caption(f"… and {len(result.changes) - 50} more (download the full audit below).")
st.markdown("**Handled preview (first 10 rows)**")
st.dataframe(result.handled_df.head(10), width="stretch")
# ---------------------------------------------------------------------------
# Downloads
# ---------------------------------------------------------------------------
#
# Rendered via ``html_download_button`` (raw <a download> anchor) rather
# than ``st.download_button``. The latter has a long-standing bug where
# the second and third download_buttons rendered in the same script pass
# fail to fire — only the first one's click reaches the browser save
# dialog. The HTML helper bypasses the widget system entirely and works
# uniformly across all browsers. The empty-changes case still renders a
# disabled button (rather than vanishing) so the layout stays steady and
# the user understands why nothing's available.
st.divider()
stem = Path(st.session_state.get("missing_input_name", "input")).stem
handled_bytes = result.handled_df.to_csv(index=False).encode("utf-8-sig")
changes_bytes = (
result.changes.to_csv(index=False).encode("utf-8-sig")
if not result.changes.empty
else b""
)
config_bytes = json.dumps(
st.session_state.get("missing_options", {}), indent=2, default=str,
).encode("utf-8")
dl_a, dl_b, dl_c = st.columns(3)
with dl_a:
html_download_button(
"Download handled CSV",
handled_bytes,
file_name=f"{stem}_missing.csv",
mime="text/csv",
)
with dl_b:
html_download_button(
"Download changes audit",
changes_bytes,
file_name=f"{stem}_missing_changes.csv",
mime="text/csv",
disabled=result.changes.empty,
help="No changes to audit." if result.changes.empty else None,
)
with dl_c:
html_download_button(
"Download config JSON",
config_bytes,
file_name="missing_config.json",
mime="application/json",
)
# ---------------------------------------------------------------------------
# Post-run auto-scroll
# ---------------------------------------------------------------------------
#
# When the user clicks Handle Missing Values, the preview + options
# collapse but Streamlit by itself doesn't scroll — the Results section
# is at the bottom of a tall script so the user has to find it. Inject
# a tiny component-html iframe that calls ``scrollIntoView`` on the
# parent's Results anchor. Streamlit's main page is same-origin with
# component iframes so ``window.parent.document`` access is allowed.
#
# The flag is one-shot (``pop`` removes it) so re-renders triggered by
# unrelated widgets in the Results section don't yank the viewport
# back to the top of Results.
if st.session_state.pop("_missing_scroll_to_results", False):
st.iframe(
"""
<script>
const doc = window.parent.document;
const target = doc.getElementById('missing-results-anchor');
if (target) target.scrollIntoView({behavior: 'smooth', block: 'start'});
</script>
""",
height=1,
)