Prerelease 1.37.0: new api example apps (#1119)

* Unstacked bar chart example

* area chart stacking example

* st.feedback examples

* Change apps to nightly

Author: sfc-gh-dmatthews

python/api-examples-source/charts.area_chart_steamgraph.py

@@ -0,0 +1,6 @@
+import streamlit as st
+from vega_datasets import data
+
+source = data.unemployment_across_industries()
+
+st.area_chart(source, x="date", y="count", color="series", stack="center")

python/api-examples-source/charts.bar_chart_unstacked.py

@@ -0,0 +1,6 @@
+import streamlit as st
+from vega_datasets import data
+
+source = data.barley()
+
+st.bar_chart(source, x="year", y="yield", color="site", stack=False)

python/api-examples-source/requirements.txt

@@ -11,4 +11,4 @@ pydeck==0.8.0
 Faker==19.1.0
 openai==1.3.0
 vega_datasets
-streamlit==1.36.0
+streamlit-nightly

python/api-examples-source/widgets.feedback_stars.py

@@ -0,0 +1,6 @@
+import streamlit as st
+
+sentiment_mapping = ["one", "two", "three", "four", "five"]
+selected = st.feedback("stars")
+if selected is not None:
+    st.markdown(f"You selected {sentiment_mapping[selected]} star(s).")

python/api-examples-source/widgets.feedback_thumbs.py

@@ -0,0 +1,6 @@
+import streamlit as st
+
+sentiment_mapping = [":material/thumb_down:", ":material/thumb_up:"]
+selected = st.feedback("thumbs")
+if selected is not None:
+    st.markdown(f"You selected: {sentiment_mapping[selected]}")