Add plotting functionality

code/processing/dataframe.py

@@ -0,0 +1,45 @@
+from app import db
+from io import BytesIO
+from pandas import DataFrame, read_sql
+from base64 import b64encode
+
+
+def create_dataframe(query) -> DataFrame:
+    df = read_sql(sql=query, con=db.engine)
+    return df
+
+
+def render_table(df) -> str:
+    df.fillna(value=0, inplace=True)
+    table = df.to_html(classes=["table-striped", "table-hover"])
+    return table
+
+
+def render_plot(df):
+    df.fillna(value=0, inplace=True)
+    plot = df.plot("year", ["surface", "length", "elevation"], kind="bar")
+    plot_figure = plot.get_figure()
+    figure = BytesIO()
+    plot_figure.savefig(figure)
+    figure.seek(0)
+    return figure
+
+
+def encode_plot(plot):
+    buffer = b"".join(plot)
+    buf = b64encode(buffer)
+    encoded_plot = buf.decode("utf-8")
+    return encoded_plot
+
+
+def create_table(query) -> str:
+    df = create_dataframe(query)
+    html_table = render_table(df)
+    return html_table
+
+
+def create_plot(query):
+    df = create_dataframe(query)
+    plot = render_plot(df)
+    encoded_plot = encode_plot(plot)
+    return encoded_plot

code/processing/tabulate.py

@@ -1,19 +0,0 @@
-from app import db
-from pandas import DataFrame, read_sql
-
-
-def create_dataframe(query) -> DataFrame:
-    df = read_sql(sql=query, con=db.engine)
-    return df
-
-
-def render_table(df) -> str:
-    df.fillna(value=0, inplace=True)
-    table = df.to_html(classes=["table-striped", "table-hover"])
-    return table
-
-
-def create_table(query) -> str:
-    df = create_dataframe(query)
-    html_table = render_table(df)
-    return html_table