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🆒  Echo Expander

Submitted by Brian Hess

Summary

Execute code, and show the code that was executed, but in an expander.

Functions

echo_expander

Execute code, and show the code that was executed, but in an expander.

Parameters:

Name Type Description Default
code_location str

Whether to show the echoed code above or below. Defaults to "above".

 'above'
expander bool

Whether the code block should occur in an expander. Defaults to True.

 True
label str

If expander is True, then the label for the expander. Defaults to "Show code".

 'Show code'
Source code in src/streamlit_extras/echo_expander/__init__.py 
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@extra
@contextlib.contextmanager
def echo_expander(code_location="above", expander=True, label="Show code"):
    """
    Execute code, and show the code that was executed, but in an expander.

    Args:
        code_location (str, optional): Whether to show the echoed code above or below. Defaults to "above".
        expander (bool, optional): Whether the code block should occur in an expander. Defaults to True.
        label (str, optional): If expander is True, then the label for the expander. Defaults to "Show code".
    """

    from streamlit import empty, source_util

    if code_location == "above":
        placeholder = empty()
    else:
        placeholder = st

    try:
        # Get stack frame *before* running the echoed code. The frame's
        # line number will point to the `st.echo` statement we're running.
        frame = traceback.extract_stack()[-3]
        filename, start_line = frame.filename, frame.lineno

        # Read the file containing the source code of the echoed statement.
        with source_util.open_python_file(filename) as source_file:
            source_lines = source_file.readlines()

        # Use ast to parse the Python file and find the code block to display
        import ast

        ap = ast.parse("".join(source_lines))

        ap_map = {}

        def map_ast(a):
            if not hasattr(a, "body"):
                return
            for b in a.body:
                ap_map[b.lineno] = b
                map_ast(b)

        map_ast(ap)
        lines_to_display = source_lines[
            ap_map[start_line].body[0].lineno - 1 : ap_map[start_line].end_lineno
        ]
        code_string = textwrap.dedent("".join(lines_to_display))

        # Run the echoed code...
        yield

        # And draw the code string to the app!
        if expander:
            placeholder.expander(label).code(code_string, "python")
        else:
            placeholder.code(code_string, "python")

    except FileNotFoundError as err:
        placeholder.warning("Unable to display code. %s" % err)

Import:

from streamlit_extras.echo_expander import echo_expander # (1)!
  1. You should add this to the top of your .py file 🛠

Examples

example1

def example1():
    with echo_expander():
        import streamlit as st

        st.markdown(
            """
            This component is a combination of `st.echo` and `st.expander`.
            The code inside the `with echo_expander()` block will be executed,
            and the code can be shown/hidden behind an expander
            """
        )
Output (beta)

example2

def example2():
    with echo_expander(code_location="below", label="Simple Dataframe example"):
        import pandas as pd
        import streamlit as st

        df = pd.DataFrame(
            [[1, 2, 3, 4, 5], [11, 12, 13, 14, 15]],
            columns=("A", "B", "C", "D", "E"),
        )
        st.dataframe(df)
Output (beta)