Typeerrr : apply_move() missing 1 required positional argument 'list' for using from streamlit_dnd import apply_move, dnd

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Welcome to the Streamlit community, and thanks for sharing your code and error! :blush: The error occurs because the apply_move() function from the streamlit-dnd package expects two arguments: the event dictionary (from dnd()) and the list(s) you want to update, but your code is only passing one argument. Also, the drag-and-drop functionality provided by streamlit-dnd works for reordering or moving items between containers, not for dragging entire DataFrames between containers. You can, however, drag and drop list items (e.g., row names) between containers.

Here’s a corrected and minimal example for drag-and-drop of row names between two containers using streamlit-dnd (not full DataFrames):

import streamlit as st
import pandas as pd
from streamlit_dnd import dnd, apply_move

st.title("Multiple Excel Drag-and-Drop Loader")

# 1. Upload multiple Excel files
uploaded_files = st.file_uploader(
    "Choose Excel files", type=["xlsx"], accept_multiple_files=True
)

# 2. Initialize session state for two containers
if "container_a" not in st.session_state:
    st.session_state.container_a = []
if "container_b" not in st.session_state:
    st.session_state.container_b = []

# 3. Load data from uploaded files into container_a
if uploaded_files:
    rows = []
    for file in uploaded_files:
        df = pd.read_excel(file)
        rows.extend(df.iloc[:, 0].dropna().astype(str).tolist()[:10])
    st.session_state.container_a = rows
    st.session_state.container_b = []

# 4. Render containers and enable drag-and-drop
with st.container(key="container_a", border=True):
    st.write("Container A")
    for item in st.session_state.container_a:
        with st.container(key=f"item_a_{item}", border=True):
            st.write(item)

with st.container(key="container_b", border=True):
    st.write("Container B")
    for item in st.session_state.container_b:
        with st.container(key=f"item_b_{item}", border=True):
            st.write(item)

# 5. Activate drag-and-drop and apply moves
event = dnd("container_a", "container_b")
if event:
    apply_move(event, st.session_state)
    st.rerun()

This will let you drag row names between two containers. For full DataFrame drag-and-drop, Streamlit does not natively support this—only list items can be moved using streamlit-dnd (see streamlit-dnd docs and demo).

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