Merge pull request #754 from realpython/altair-python

Sample code for the article on Altair

Author: lpozo

altair-python/README.md

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+# Altair: Declarative Charts With Python
+
+This folder provides the code examples for the Real Python tutorial [Altair: Declarative Charts With Python](https://realpython.com/altair-python/).

altair-python/altair-python.ipynb

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+import altair as alt
+from altair.datasets import data
+
+movies = data.movies()
+movies = movies.dropna(
+    subset=[
+        "Production Budget",
+        "Worldwide Gross",
+    ]
+)
+
+scatter = (
+    alt.Chart(movies)
+    .mark_point()
+    .encode(
+        x="Production Budget:Q",
+        y="Worldwide Gross:Q",
+    )
+)
+scatter

altair-python/scatter_basic.py

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+import altair as alt
+from altair.datasets import data
+
+movies = data.movies()
+movies = movies.dropna(
+    subset=[
+        "Production Budget",
+        "Worldwide Gross",
+        "IMDB Rating",
+        "Major Genre",
+    ]
+)
+
+brush = alt.selection_interval()
+
+scatter = (
+    alt.Chart(movies)
+    .mark_point()
+    .encode(
+        x="Production Budget:Q",
+        y="Worldwide Gross:Q",
+        color=(
+            alt.when(brush)
+            .then("Major Genre:N")
+            .otherwise(alt.value("lightgray")),
+        ),
+    )
+    .add_params(brush)
+)
+
+scatter
+
+bars = (
+    alt.Chart(movies)
+    .mark_bar()
+    .encode(
+        x="mean(IMDB Rating):Q",
+        y="Major Genre:N",
+    )
+    .transform_filter(brush)
+)
+
+scatter & bars

altair-python/scatter_connected.py

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+import altair as alt
+from altair.datasets import data
+
+movies = data.movies()
+movies = movies.dropna(
+    subset=[
+        "Production Budget",
+        "Worldwide Gross",
+        "IMDB Rating",
+        "Major Genre",
+    ]
+)
+
+scatter = (
+    alt.Chart(movies)
+    .mark_point()
+    .encode(
+        x="Production Budget:Q",
+        y="Worldwide Gross:Q",
+        color="Major Genre:N",
+        size="IMDB Rating:Q",
+        tooltip=["Title:N", "IMDB Rating:Q"],
+    )
+)
+scatter

altair-python/scatter_encoding_channels.py

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+import altair as alt
+from altair.datasets import data
+
+movies = data.movies()
+movies = movies.dropna(
+    subset=[
+        "Production Budget",
+        "Worldwide Gross",
+        "IMDB Rating",
+        "Major Genre",
+        "MPAA Rating",
+    ]
+)
+
+scatter = (
+    alt.Chart(movies)
+    .mark_point()
+    .encode(
+        x="Production Budget:Q",
+        y="Worldwide Gross:Q",
+        color="Major Genre:N",
+        size="IMDB Rating:Q",
+        tooltip=["Title:N", "IMDB Rating:Q"],
+        column="MPAA Rating:O",
+    )
+)
+scatter

altair-python/scatter_faceted.py

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+import altair as alt
+import pandas as pd
+
+steps = pd.DataFrame(
+    {
+        "Day": ["1-Mon", "2-Tue", "3-Wed", "4-Thu", "5-Fri", "6-Sat", "7-Sun"],
+        "Steps": [6200, 8400, 7100, 9800, 5500, 9870, 3769],
+    }
+)
+
+weekly_steps = (
+    alt.Chart(steps)
+    .mark_bar()
+    .encode(
+        x="Day",
+        y="Steps",
+    )
+)
+weekly_steps