Update app.py

app.py

@@ -2,37 +2,48 @@ import streamlit as st
 import pandas as pd
 
 # Streamlit App
-st.title('CSV Column Selector')
-
-# File uploader for CSV files
-uploaded_file = st.file_uploader("Upload CSV file", type=["csv"])
-
-if uploaded_file is not None:
-    # Read the CSV file into a DataFrame
-    df = pd.read_csv(uploaded_file)
-    
-    # Display the original DataFrame
-    st.subheader('Original DataFrame')
-    st.write(df)
-
-    # Column selection for inclusion
-    st.subheader('Select Columns to Include')
-    include_columns = st.multiselect('Select columns to include', options=df.columns, default=df.columns.tolist())
-
-    # Filter DataFrame to include only selected columns
-    if include_columns:
-        filtered_df = df[include_columns]
-    else:
-        filtered_df = df
-
-    # Display the filtered DataFrame
-    st.subheader('Filtered DataFrame')
-    st.write(filtered_df)
-    
-    # Option to download the filtered DataFrame
-    st.download_button(
-        label="Download Filtered DataFrame",
-        data=filtered_df.to_csv(index=False),
-        file_name='filtered_data.csv',
-        mime='text/csv'
-    )
+st.title('CSV File Merger')
+
+# File uploaders for multiple CSV files
+uploaded_files = st.file_uploader("Upload CSV files", type=["csv"], accept_multiple_files=True)
+
+# Dropdown to select merge type
+merge_type = st.selectbox("Select merge type", ["inner", "outer", "left", "right"])
+
+# Text input for common column name
+common_column = st.text_input("Enter the common column name")
+
+if len(uploaded_files) > 1 and common_column:
+    # Read all uploaded CSV files into a list of DataFrames
+    dfs = [pd.read_csv(file) for file in uploaded_files]
+
+    # Display the original DataFrames
+    st.subheader('Original DataFrames')
+    for i, df in enumerate(dfs):
+        st.write(f"DataFrame {i + 1}:")
+        st.write(df)
+
+    try:
+        # Perform the merge based on the selected type and common column
+        merged_df = dfs[0]
+        for df in dfs[1:]:
+            merged_df = pd.merge(merged_df, df, on=common_column, how=merge_type)
+        
+        # Display the merged DataFrame
+        st.subheader('Merged DataFrame')
+        st.write(merged_df)
+
+        # Option to download the merged DataFrame
+        st.download_button(
+            label="Download Merged DataFrame",
+            data=merged_df.to_csv(index=False),
+            file_name='merged_data.csv',
+            mime='text/csv'
+        )
+    except KeyError:
+        st.error(f"Column '{common_column}' not found in one or more files.")
+    except Exception as e:
+        st.error(f"An error occurred: {e}")
+
+else:
+    st.info("Please upload at least two CSV files and specify the common column name.")