added streamlit v1
This commit is contained in:
Binary file not shown.
@@ -1,6 +1,4 @@
|
||||
You are an expert policy analyst classifying public comments submitted to the Virginia Town Hall
|
||||
regulatory comment system. You will be given the text of a proposed regulation and a single
|
||||
public comment. Return ONLY a JSON object — no other text.
|
||||
You are an expert policy analyst classifying public comments submitted to the Virginia Town Hall regulatory comment system. You will be given the text of a proposed regulation and a single public comment. Return ONLY a JSON object — no other text.
|
||||
|
||||
Definitions:
|
||||
- stance: the commenter's position on whether the regulation should be adopted.
|
||||
@@ -16,8 +14,6 @@ Definitions:
|
||||
"unclear" = tone cannot be determined (e.g., a one-word comment).
|
||||
- stance_confidence: float 0.0-1.0, your confidence in the stance label.
|
||||
- stance_rationale: 1-3 sentences explaining the key evidence; quote specific phrases where possible.
|
||||
- tags: up to 5 short topic labels relevant to the comment's specific concerns (e.g.
|
||||
"parental rights", "student safety", "privacy", "religious freedom", "LGBTQ+ inclusion",
|
||||
"bullying prevention", "school sports", "bathroom access"). Empty array if none apply.
|
||||
- tags: up to 5 short topic labels relevant to the comment's specific concerns (e.g. "parental rights", "student safety", "privacy", "religious freedom", "LGBTQ inclusion", "bullying prevention", "school sports", "bathroom access"). Empty array if none apply.
|
||||
|
||||
Return exactly these keys: stance, stance_confidence, stance_rationale, tone, tags.
|
||||
|
||||
@@ -280,10 +280,10 @@ python analysis/create_csv.py output/f452.jsonl analysis/jobs/f452-1/ --parquet
|
||||
#+end_src
|
||||
|
||||
** evidence
|
||||
- commit:
|
||||
- commit: 28d6d22
|
||||
- tests: passing (pytest tests/create_csv.py tests/encoding.py)
|
||||
- csv: analysis/jobs/f452-1/review.csv
|
||||
- datetime: [2026-05-07 Thu]
|
||||
- datetime: [2026-05-07 Thu 17:23]
|
||||
|
||||
* [X] t1.1.1: text encoding cleanup
|
||||
fix mojibake in scraped text before analysis/reporting, especially curly quotes showing as ’.
|
||||
@@ -309,13 +309,33 @@ fix mojibake in scraped text before analysis/reporting, especially curly quotes
|
||||
- Spider: DEFAULT_RESPONSE_ENCODING=utf-8 remains. If a future forum genuinely sends cp1252, change to 'cp1252' and apply ftfy post-decode in the item pipeline.
|
||||
|
||||
** evidence
|
||||
- commit:
|
||||
- commit: 1ea696d
|
||||
- tests: passing (pytest tests/encoding.py)
|
||||
- before/after sample: N/A — f452.jsonl is clean; tests cover synthetic mojibake patterns
|
||||
- datetime: [2026-05-07 Thu]
|
||||
* === Backlog ===
|
||||
* [ ] X: first dash explorer
|
||||
create a local dash app for exploring one forum analysis dataset.
|
||||
- datetime: [2026-05-07 Thu 17:00]
|
||||
|
||||
* [ ] t1.4: graph data prep
|
||||
create a script ./viz/prototype_charts.py generating individual plotly charts for exploring graphs to embed into streamlit or dash later
|
||||
1. in create_csv.py, create helper columns:
|
||||
- stance_signed = {"support":1, "oppose":-1, "neutral":0, "unknown":0}
|
||||
- stance_weighted = stance_signed * stance_confidence
|
||||
- is_support_oppose = stance in ["support", "oppose"]
|
||||
- date_day
|
||||
- date_hour
|
||||
- text_norm
|
||||
- text_hash
|
||||
- confidence_bucket = 'low' <.7 | 'med' .7-.89 | 'high' >=.9
|
||||
|
||||
2. add forum_url, forum_collected_date to scraper
|
||||
|
||||
2. create graph for Stance/Share
|
||||
- stacked h-bar with % support/oppose/neutral/unknown + raw totals, eg 63% (5720) / 37% (3320) / 0.09% (8) / 0.37% (34)
|
||||
- later, consider centered diverging h-bar: oppose ← | neutral/unknown | → support
|
||||
3. create graph for Stance/Time:
|
||||
- cumulative support/oppose % over time
|
||||
4. create graph for Stance/Tone (heatmap count)
|
||||
5. create graph for Confidence/Stance (boxplot or histogram)
|
||||
|
||||
|
||||
** acceptance criteria
|
||||
1. load parquet/csv review dataset
|
||||
@@ -324,6 +344,16 @@ create a local dash app for exploring one forum analysis dataset.
|
||||
4. show filtered comment table
|
||||
5. clicking/selecting a comment shows full text and model rationale
|
||||
6. app runs locally with one command
|
||||
|
||||
** notes
|
||||
|
||||
** evidence
|
||||
- commit:
|
||||
- tests:
|
||||
- datetime:
|
||||
|
||||
* === Backlog ===
|
||||
|
||||
* [ ] X: complete proposal information
|
||||
Ensure we capture as much useful information as possible about the actual proposal - contact information, etc. what the state actually says about what was posted.
|
||||
** acceptance criteria
|
||||
|
||||
3888
viz/chart_tests/confidence_by_stance.html
Normal file
3888
viz/chart_tests/confidence_by_stance.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/cumulative_stance_area.html
Normal file
3888
viz/chart_tests/cumulative_stance_area.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/cumulative_stance_share.html
Normal file
3888
viz/chart_tests/cumulative_stance_share.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_diverging_bar.html
Normal file
3888
viz/chart_tests/stance_diverging_bar.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_over_time.html
Normal file
3888
viz/chart_tests/stance_over_time.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_share.html
Normal file
3888
viz/chart_tests/stance_share.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_tone_counts.html
Normal file
3888
viz/chart_tests/stance_tone_counts.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_tone_heatmap.html
Normal file
3888
viz/chart_tests/stance_tone_heatmap.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/chart_tests/stance_tone_rowpct.html
Normal file
3888
viz/chart_tests/stance_tone_rowpct.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/proto/confidence_by_stance.html
Normal file
3888
viz/proto/confidence_by_stance.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/proto/stance_over_time.html
Normal file
3888
viz/proto/stance_over_time.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/proto/stance_share.html
Normal file
3888
viz/proto/stance_share.html
Normal file
File diff suppressed because one or more lines are too long
3888
viz/proto/stance_tone_heatmap.html
Normal file
3888
viz/proto/stance_tone_heatmap.html
Normal file
File diff suppressed because one or more lines are too long
134
viz/prototype_charts.py
Normal file
134
viz/prototype_charts.py
Normal file
@@ -0,0 +1,134 @@
|
||||
'''
|
||||
prototype_charts.py
|
||||
generate test charts for later addition to streamlit
|
||||
'''
|
||||
|
||||
|
||||
from pathlib import Path
|
||||
import pandas as pd
|
||||
import plotly.express as px
|
||||
import numpy as np
|
||||
|
||||
inp = Path(r"c:/users/moses/projects/vath/analysis/jobs/f452-1/review.csv")
|
||||
out = Path("viz/")
|
||||
out.mkdir(parents=True, exist_ok=True)
|
||||
|
||||
stance_order = ["support", "oppose", "neutral", "unknown"]
|
||||
|
||||
# tone_order = ["positive", "negative", "neutral", "mixed", "unknown", "unclear"]
|
||||
# default order was actually better - unclear/negative/neutral/mixed/positive vs unknown/oppose/neutral/support
|
||||
# same for pct w/in stance
|
||||
df = pd.read_csv(inp)
|
||||
df["date"] = pd.to_datetime(df["date"], errors="coerce")
|
||||
df["date_day"] = df["date"].dt.date
|
||||
df["stance"] = df["stance"].fillna("unknown")
|
||||
df["tone"] = df["tone"].fillna("unknown")
|
||||
|
||||
# 1. stance share
|
||||
counts = df["stance"].value_counts().reindex(stance_order, fill_value=0).reset_index()
|
||||
counts.columns = ["stance", "count"]
|
||||
fig = px.bar(counts, x="count", y="stance", orientation="h", text="count")
|
||||
fig.write_html(out / "stance_share.html")
|
||||
|
||||
# 2. stance over time
|
||||
daily = df.groupby(["date_day", "stance"]).size().reset_index(name="count")
|
||||
fig = px.bar(daily, x="date_day", y="count", color="stance", category_orders={"stance": stance_order})
|
||||
fig.write_html(out / "stance_over_time.html")
|
||||
|
||||
# 3. stance x tone
|
||||
heat = df.groupby(["stance", "tone"]).size().reset_index(name="count")
|
||||
fig = px.density_heatmap(heat, x="tone", y="stance", z="count", category_orders={"stance": stance_order})
|
||||
fig.write_html(out / "stance_tone_heatmap.html")
|
||||
|
||||
# 4. confidence by stance
|
||||
fig = px.box(df, x="stance", y="stance_confidence", category_orders={"stance": stance_order}, points="outliers")
|
||||
fig.write_html(out / "confidence_by_stance.html")
|
||||
|
||||
# 5. cumulative stance and share over time
|
||||
daily = (
|
||||
df.groupby(["date_day", "stance"])
|
||||
.size()
|
||||
.unstack(fill_value=0)
|
||||
.reindex(columns=stance_order, fill_value=0)
|
||||
.sort_index()
|
||||
)
|
||||
|
||||
cum = daily.cumsum()
|
||||
cum_long = cum.reset_index().melt(id_vars="date_day", var_name="stance", value_name="cumulative_count")
|
||||
|
||||
fig = px.area(
|
||||
cum_long,
|
||||
x="date_day",
|
||||
y="cumulative_count",
|
||||
color="stance",
|
||||
category_orders={"stance": stance_order},
|
||||
title="cumulative comments by stance over time",
|
||||
)
|
||||
fig.write_html(out / "cumulative_stance_area.html")
|
||||
|
||||
cum_pct = cum.div(cum.sum(axis=1), axis=0).reset_index().melt(
|
||||
id_vars="date_day", var_name="stance", value_name="cumulative_share"
|
||||
)
|
||||
|
||||
fig = px.line(
|
||||
cum_pct,
|
||||
x="date_day",
|
||||
y="cumulative_share",
|
||||
color="stance",
|
||||
category_orders={"stance": stance_order},
|
||||
title="cumulative stance share over time",
|
||||
)
|
||||
fig.update_yaxes(tickformat=".0%")
|
||||
fig.write_html(out / "cumulative_stance_share.html")
|
||||
|
||||
# 7. diverging h-bar
|
||||
stance_counts = df["stance"].value_counts().reindex(stance_order, fill_value=0)
|
||||
|
||||
div = pd.DataFrame({
|
||||
"stance": ["oppose", "support", "neutral", "unknown"],
|
||||
"count": [
|
||||
-stance_counts.get("oppose", 0),
|
||||
stance_counts.get("support", 0),
|
||||
stance_counts.get("neutral", 0),
|
||||
stance_counts.get("unknown", 0),
|
||||
],
|
||||
})
|
||||
|
||||
fig = px.bar(
|
||||
div,
|
||||
x="count",
|
||||
y="stance",
|
||||
orientation="h",
|
||||
text=div["count"].abs(),
|
||||
title="support vs oppose",
|
||||
)
|
||||
fig.update_xaxes(title="comments", zeroline=True)
|
||||
fig.update_traces(textposition="outside")
|
||||
fig.write_html(out / "stance_diverging_bar.html")
|
||||
|
||||
# 8. Stance x Tone labels
|
||||
heat = pd.crosstab(df["stance"], df["tone"]).reindex(
|
||||
index=stance_order,
|
||||
columns=[c for c in tone_order if c in df["tone"].unique()],
|
||||
fill_value=0,
|
||||
)
|
||||
|
||||
fig = px.imshow(
|
||||
heat,
|
||||
text_auto=True,
|
||||
aspect="auto",
|
||||
title="stance x tone, count",
|
||||
)
|
||||
fig.write_html(out / "stance_tone_counts.html")
|
||||
|
||||
rowpct = heat.div(heat.sum(axis=1).replace(0, np.nan), axis=0)
|
||||
|
||||
fig = px.imshow(
|
||||
rowpct,
|
||||
text_auto=".0%",
|
||||
aspect="auto",
|
||||
title="stance x tone, percent within stance",
|
||||
)
|
||||
fig.write_html(out / "stance_tone_rowpct.html")
|
||||
|
||||
|
||||
28
viz/prototype_streamlit.py
Normal file
28
viz/prototype_streamlit.py
Normal file
@@ -0,0 +1,28 @@
|
||||
# streamlit run analysis/viz/prototype_streamlit.py
|
||||
from datetime import datetime
|
||||
import pandas as pd
|
||||
import plotly.graph_objects as go
|
||||
import plotly.express as px
|
||||
import streamlit as st
|
||||
|
||||
df = pd.read_csv(r"analysis/jobs/f452-1/review.csv")
|
||||
st.set_page_config(layout="wide")
|
||||
|
||||
stance = st.multiselect("Filter stance", sorted(df["stance"].dropna().unique()), default=sorted(df["stance"].dropna().unique()))
|
||||
q = st.text_input("Search comment text")
|
||||
dff = df[df["stance"].isin(stance)]
|
||||
if q:
|
||||
dff = dff[dff["text"].fillna("").str.contains(q, case=False, regex=False)]
|
||||
|
||||
st.dataframe(dff[["comment_id", "title", "stance", "stance_confidence", "tone"]], width="stretch")
|
||||
st.write("Showing " + str(len(dff))+ " comments")
|
||||
|
||||
cid = st.selectbox("comment", dff["comment_id"].astype(str))
|
||||
row = dff[dff["comment_id"].astype(str) == cid].iloc[0]
|
||||
|
||||
st.subheader(row["title"])
|
||||
st.write(row["text"])
|
||||
st.write(row["author"] + ", " + row["date"][:10])
|
||||
st.write("**model:** " + str(row["model"]))
|
||||
st.markdown("**stance:** " + str(row["stance"]) + " \n**confidence:** " + str(row["stance_confidence"]) + " \n**tone:** " + str(row["tone"]))
|
||||
st.write("**analysis:** "+ row["stance_rationale"])
|
||||
177
viz/streamlit.py
Normal file
177
viz/streamlit.py
Normal file
@@ -0,0 +1,177 @@
|
||||
# streamlit run analysis/viz/comment_streamlit2.py
|
||||
from datetime import datetime as dt
|
||||
from pathlib import Path
|
||||
import pandas as pd
|
||||
import plotly.graph_objects as go
|
||||
import plotly.express as px
|
||||
import plotly.subplots as ps
|
||||
import streamlit as st
|
||||
|
||||
workdir = Path("analysis/jobs/f452-1")
|
||||
df = pd.read_csv(workdir/"review.csv")
|
||||
df['date_dt'] = pd.to_datetime(df.date)
|
||||
df["date_day"] = df["date_dt"].dt.date
|
||||
forum = pd.read_json(workdir/"forum.jsonl", lines=True).iloc[0].to_dict()
|
||||
prompt = (workdir/"prompt.txt").read_text(encoding="utf-8")
|
||||
|
||||
stance_colors = {'oppose':'#ffa15a', 'neutral':'#e377c2','support':'#19d3f3','unknown':'#000000'}
|
||||
#stance_colors = {'oppose':'orange', 'neutral':'green','support':'blue','unknown':'gray','mixed':'violet'}
|
||||
stance_order = ["oppose", "neutral", "unknown", "support"]
|
||||
|
||||
st.set_page_config(layout="wide")
|
||||
st.title("Virginia Townhall Explorer")
|
||||
st.divider()
|
||||
st.subheader(forum.get('reg_title'))
|
||||
st.text(forum.get('reg_desc'))
|
||||
st.caption(f"Link: https://www.townhall.virginia.gov/L/Comments.cfm?GDocForumID={forum.get('forum_id')}")
|
||||
|
||||
st.write(f'Comments posted from {dt.strftime(min(df.date_dt),"%D")}—{dt.strftime(max(df.date_dt),"%D")}')
|
||||
st.write('Data collected on _')
|
||||
|
||||
st.subheader("Comment Summary")
|
||||
# summary
|
||||
summary_left, summary_right = st.columns([1,2])
|
||||
with summary_left:
|
||||
# summary table
|
||||
#summary_stats = df.groupby("stance").size().reindex(stance_order,fill_value=0).reset_index(name="count")
|
||||
summary_stats = (
|
||||
df.groupby("stance").size()
|
||||
.reindex(stance_order, fill_value=0)
|
||||
.reset_index(name="count")
|
||||
.assign(percent=lambda d: (d["count"] / d["count"].sum()).map("{:.1%}".format))
|
||||
)
|
||||
|
||||
st.dataframe(summary_stats, hide_index=True, width="stretch")
|
||||
with summary_right:
|
||||
# stance div-h
|
||||
counts = df["stance"].value_counts()
|
||||
stance_divh = go.Figure()
|
||||
stance_divh.add_bar(y=["stance"], x=[-counts.get("oppose",0)], name="oppose", orientation="h", marker_color=stance_colors.get('oppose'), text=[counts.get("oppose",0)], textposition="inside")
|
||||
stance_divh.add_bar(y=["stance"], x=[counts.get("neutral",0)], name="neutral", orientation="h", marker_color=stance_colors.get('neutral'), text=[counts.get("neutral",0)], textposition="inside")
|
||||
stance_divh.add_bar(y=["stance"], x=[counts.get("unknown",0)], name="unknown", orientation="h", marker_color=stance_colors.get('unknown'), text=[counts.get("unknown",0)], textposition="inside")
|
||||
stance_divh.add_bar(y=["stance"], x=[counts.get("support",0)], name="support", orientation="h", marker_color=stance_colors.get('support'), text=[counts.get("support",0)], textposition="inside")
|
||||
stance_divh.update_yaxes(title_text="",showticklabels=False)
|
||||
stance_divh.update_layout(barmode="relative", title="", height=180, margin=dict(l=0,r=0,t=0,b=0),xaxis_title="", yaxis_title="",legend=dict(orientation="v",y=0.12))
|
||||
#legend_orientation="v")
|
||||
st.plotly_chart(stance_divh,width='stretch')
|
||||
|
||||
# stance_time
|
||||
#stance_order = ["oppose", "neutral","unknown","support"]
|
||||
#daily = df.groupby(["date_day", "stance"]).size().reset_index(name="count")
|
||||
#stance_time = px.bar(daily, x="date_day", y="count", color="stance", category_orders={"stance": stance_order},color_discrete_map=stance_colors,title="")
|
||||
#st.plotly_chart(stance_time, width='stretch')
|
||||
|
||||
# Daily Comments Breakdown, 3 Tabs
|
||||
daily_wide = (
|
||||
df.groupby(["date_day", "stance"])
|
||||
.size()
|
||||
.unstack(fill_value=0)
|
||||
.reindex(columns=stance_order, fill_value=0)
|
||||
.sort_index()
|
||||
)
|
||||
|
||||
daily_long = (
|
||||
daily_wide.reset_index()
|
||||
.melt(id_vars="date_day", var_name="stance", value_name="count")
|
||||
)
|
||||
|
||||
cum_wide = daily_wide.cumsum()
|
||||
|
||||
cum_long = (
|
||||
cum_wide.reset_index()
|
||||
.melt(id_vars="date_day", var_name="stance", value_name="cumulative_count")
|
||||
)
|
||||
|
||||
cum_total = cum_wide.sum(axis=1)
|
||||
cum_share = cum_wide.div(cum_total.where(cum_total > 0), axis=0)
|
||||
|
||||
cum_share_long = (
|
||||
cum_share.reset_index()
|
||||
.melt(id_vars="date_day", var_name="stance", value_name="cumulative_share")
|
||||
)
|
||||
|
||||
tab_daily, tab_area, tab_share = st.tabs([
|
||||
"Daily",
|
||||
"Cumulative",
|
||||
"Cumulative Share",
|
||||
])
|
||||
|
||||
with tab_daily:
|
||||
fig = px.bar(
|
||||
daily_long,
|
||||
x="date_day",
|
||||
y="count",
|
||||
color="stance",
|
||||
category_orders={"stance": stance_order},
|
||||
color_discrete_map=stance_colors,
|
||||
)
|
||||
fig.update_layout(barmode="stack", height=420, legend_orientation="v")
|
||||
st.plotly_chart(fig, width="stretch")
|
||||
|
||||
with tab_area:
|
||||
fig = px.area(
|
||||
cum_long,
|
||||
x="date_day",
|
||||
y="cumulative_count",
|
||||
color="stance",
|
||||
category_orders={"stance": stance_order},
|
||||
color_discrete_map=stance_colors,
|
||||
)
|
||||
fig.update_layout(height=420, legend_orientation="v")
|
||||
st.plotly_chart(fig, width="stretch")
|
||||
|
||||
with tab_share:
|
||||
fig = px.line(
|
||||
cum_share_long,
|
||||
x="date_day",
|
||||
y="cumulative_share",
|
||||
color="stance",
|
||||
category_orders={"stance": stance_order},
|
||||
color_discrete_map=stance_colors,
|
||||
)
|
||||
fig.update_yaxes(tickformat=".0%", range=[0, 1])
|
||||
fig.update_layout(height=420, legend_orientation="v")
|
||||
st.plotly_chart(fig, width="stretch")
|
||||
|
||||
st.subheader("Comment Explorer")
|
||||
|
||||
# stance/tone heatmap
|
||||
# TODO add raw values
|
||||
# TODO OPT add button to swap between pct/tone <> pct/stance
|
||||
x_order = ["unknown","oppose","mixed","neutral","support"] # includes mixed even if absent; harmless zero column
|
||||
y_order = ["positive","neutral","mixed","negative","unclear"]
|
||||
tab = pd.crosstab(df["tone"], df["stance"]).reindex(index=y_order, columns=x_order, fill_value=0)
|
||||
pct = tab.div(tab.sum(axis=1).replace(0, pd.NA), axis=0).fillna(0)
|
||||
fig = px.imshow(
|
||||
pct,
|
||||
x=x_order, y=y_order,
|
||||
text_auto=".0%",
|
||||
aspect="auto",
|
||||
color_continuous_scale="Greens",
|
||||
title="tone by stance, percent within tone",
|
||||
)
|
||||
fig.update_traces(text=tab.astype(str) + " / " + (pct*100).round(0).astype(int).astype(str) + "%")
|
||||
fig.update_layout(height=420, xaxis_title="stance", yaxis_title="tone")
|
||||
st.plotly_chart(fig, width='stretch')
|
||||
|
||||
# comment explorer
|
||||
stance = st.multiselect("Filter stance", sorted(df["stance"].dropna().unique()), default=sorted(df["stance"].dropna().unique()))
|
||||
q = st.text_input("Search comment text")
|
||||
dff = df[df["stance"].isin(stance)]
|
||||
if q:
|
||||
dff = dff[dff["text"].fillna("").str.contains(q, case=False, regex=False)]
|
||||
|
||||
st.dataframe(dff[["comment_id", "title", "text", "stance", "stance_confidence", "tone"]], width="stretch")
|
||||
st.write("Showing " + str(len(dff))+ " comments")
|
||||
|
||||
cid = st.selectbox("comment", dff["comment_id"].astype(str))
|
||||
row = dff[dff["comment_id"].astype(str) == cid].iloc[0]
|
||||
|
||||
st.subheader(row["title"])
|
||||
st.write(row["text"])
|
||||
st.write(row["author"] + ", " + row["date"][:10])
|
||||
st.markdown(f"**stance:** {row['stance']} \t|\t **confidence:** {row['stance_confidence']:.2f} \t|\t **tone:** {row['tone']}")
|
||||
st.write("**analysis:** "+ row["stance_rationale"])
|
||||
st.write("**model:** " + str(row["model"]))
|
||||
with st.expander("Prompt", expanded=False):
|
||||
st.code(prompt, language="text")
|
||||
Reference in New Issue
Block a user