Mutate charts
Sometimes you display a chart or dataframe and want to modify live as the app runs (for example, in a loop). Depending on what you're looking for, there are 3 different ways to do this:
- Using
st.empty
to replace a single element. - Using
st.container
orst.columns
to replace multiple elements. - Using
add_rows
to append data to specific types of elements.
Here we discuss that last case.
Function signature[source] | |
---|---|
element.add_rows(data=None, **kwargs) | |
Parameters | |
data (pandas.DataFrame, pandas.Styler, pyarrow.Table, numpy.ndarray, pyspark.sql.DataFrame, snowflake.snowpark.dataframe.DataFrame, Iterable, dict, or None) | Table to concat. Optional. Pyarrow tables are not supported by Streamlit's legacy DataFrame serialization (i.e. with config.dataFrameSerialization = "legacy"). To use pyarrow tables, please enable pyarrow by changing the config setting, config.dataFrameSerialization = "arrow". |
**kwargs (pandas.DataFrame, numpy.ndarray, Iterable, dict, or None) | The named dataset to concat. Optional. You can only pass in 1 dataset (including the one in the data parameter). |
Example
import streamlit as st import pandas as pd import numpy as np df1 = pd.DataFrame( np.random.randn(50, 20), columns=('col %d' % i for i in range(20))) my_table = st.table(df1) df2 = pd.DataFrame( np.random.randn(50, 20), columns=('col %d' % i for i in range(20))) my_table.add_rows(df2) # Now the table shown in the Streamlit app contains the data for # df1 followed by the data for df2.You can do the same thing with plots. For example, if you want to add more data to a line chart:
# Assuming df1 and df2 from the example above still exist... my_chart = st.line_chart(df1) my_chart.add_rows(df2) # Now the chart shown in the Streamlit app contains the data for # df1 followed by the data for df2.And for plots whose datasets are named, you can pass the data with a keyword argument where the key is the name:
my_chart = st.vega_lite_chart({ 'mark': 'line', 'encoding': {'x': 'a', 'y': 'b'}, 'datasets': { 'some_fancy_name': df1, # <-- named dataset }, 'data': {'name': 'some_fancy_name'}, }), my_chart.add_rows(some_fancy_name=df2) # <-- name used as keyword
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