Update src/streamlit_app.py

src/streamlit_app.py

@@ -1,16 +1,26 @@
+
 import streamlit as st
 import pandas as pd
 import re
+import io
+import tempfile
+import os
+
+# Configure Streamlit to prevent permission issues
+os.environ['STREAMLIT_SERVER_HEADLESS'] = 'true'
+os.environ['STREAMLIT_SERVER_ENABLE_CORS'] = 'false'
+os.environ['STREAMLIT_SERVER_ENABLE_XSRF_PROTECTION'] = 'false'
 
-st.set_page_config(page_title="🧪 LaTeX MCQs", layout="wide")
+st.set_page_config(
+    page_title="🧪 LaTeX MCQs", 
+    layout="wide",
+    initial_sidebar_state="collapsed"
+)
 st.title("🧪 Chemistry MCQs with LaTeX Rendering")
 
 # Helper to safely convert mixed text + LaTeX into proper LaTeX
 def format_for_latex(text):
-    """
-    Convert mixed text and LaTeX expressions into properly formatted LaTeX.
-    Handles common chemistry notation and mathematical expressions.
-    """
+    """Convert mixed text and LaTeX expressions into properly formatted LaTeX."""
     if pd.isna(text) or text == "":
         return ""
     
@@ -21,10 +31,8 @@ def format_for_latex(text):
     text = re.sub(r'\$(.*?)\$', r'\1', text)
     
     # Handle common chemistry and math patterns
-    # Preserve existing LaTeX commands
     latex_commands = r'(\\(?:ce|text|frac|sqrt|sum|int|lim|mathrm|mathbf|mathit|alpha|beta|gamma|delta|epsilon|theta|lambda|mu|pi|sigma|omega|rightarrow|leftarrow|leftrightarrow|cdot|times|div|pm|neq|leq|geq|approx|infty|partial|nabla|Delta|Omega|therefore|because)\b[^{]*(?:\{[^}]*\})*)'
     
-    # Split text preserving LaTeX commands
     parts = re.split(f'({latex_commands})', text)
     
     formatted = ""
@@ -32,17 +40,13 @@ def format_for_latex(text):
         if not part:
             continue
             
-        # Check if this part is a LaTeX command
         if re.match(r'\\[a-zA-Z]+', part):
             formatted += part
         else:
-            # Handle plain text - wrap non-empty parts
             if part.strip():
-                # Handle subscripts and superscripts in chemical formulas
-                part = re.sub(r'([A-Za-z])(\d+)', r'\1_{\2}', part)  # H2O -> H_{2}O
-                part = re.sub(r'\^(\d+)', r'^{\1}', part)  # ^2 -> ^{2}
+                part = re.sub(r'([A-Za-z])(\d+)', r'\1_{\2}', part)
+                part = re.sub(r'\^(\d+)', r'^{\1}', part)
                 
-                # Check if the part already contains LaTeX formatting
                 if not re.search(r'[{}\\]', part):
                     formatted += f"\\text{{{part}}}"
                 else:
@@ -58,7 +62,6 @@ def validate_dataframe(df):
     if missing_columns:
         return False, f"Missing required columns: {missing_columns}"
     
-    # Check for empty questions
     empty_questions = df["question_latex"].isna().sum()
     if empty_questions > 0:
         st.warning(f"⚠️ Found {empty_questions} empty questions that will be skipped.")
@@ -67,7 +70,6 @@ def validate_dataframe(df):
 
 def render_question(idx, row):
     """Render a single question with its options."""
-    # Skip if question is empty
     if pd.isna(row["question_latex"]) or str(row["question_latex"]).strip() == "":
         return
     
@@ -107,92 +109,129 @@ def render_question(idx, row):
                 st.warning(f"Error rendering option {key}: {e}")
                 st.markdown(f"{value}")
     
-
-    
     st.markdown("---")
 
-# Main app
-uploaded_file = st.file_uploader("📥 Upload Excel file with LaTeX questions", type=["xlsx", "xls"])
-
-if uploaded_file:
+def safe_read_excel(uploaded_file):
+    """Safely read Excel file with multiple fallback methods."""
     try:
-        # Show file info
-        st.info(f"📄 Loaded file: {uploaded_file.name}")
-        
+        # Method 1: Direct reading
         df = pd.read_excel(uploaded_file)
-        
-        # Validate dataframe
+        return df, None
+    except Exception as e1:
+        try:
+            # Method 2: BytesIO
+            bytes_data = uploaded_file.getvalue()
+            df = pd.read_excel(io.BytesIO(bytes_data))
+            return df, None
+        except Exception as e2:
+            try:
+                # Method 3: Temporary file in /tmp (writable in containers)
+                with tempfile.NamedTemporaryFile(delete=False, suffix='.xlsx', dir='/tmp') as tmp_file:
+                    tmp_file.write(uploaded_file.getbuffer())
+                    tmp_file.flush()
+                    
+                    df = pd.read_excel(tmp_file.name)
+                    
+                    # Cleanup
+                    try:
+                        os.unlink(tmp_file.name)
+                    except:
+                        pass
+                    
+                    return df, None
+            except Exception as e3:
+                error_msg = f"All methods failed - Method 1: {str(e1)[:100]}, Method 2: {str(e2)[:100]}, Method 3: {str(e3)[:100]}"
+                return None, error_msg
+
+# Main app
+st.markdown("""
+### 📋 Instructions
+1. Upload an Excel file (.xlsx or .xls) with your questions
+2. Make sure your file has the required columns (see sample format below)
+3. Navigate through questions using the controls
+""")
+
+uploaded_file = st.file_uploader(
+    "📥 Upload Excel file with LaTeX questions", 
+    type=["xlsx", "xls"],
+    help="Upload an Excel file containing your MCQ questions with LaTeX formatting"
+)
+
+if uploaded_file is not None:
+    st.info(f"📄 Processing: {uploaded_file.name} ({uploaded_file.size} bytes)")
+    
+    with st.spinner("🔄 Reading Excel file..."):
+        df, error_msg = safe_read_excel(uploaded_file)
+    
+    if df is None:
+        st.error(f"❌ Error: {error_msg}")
+        st.markdown("### Troubleshooting:")
+        st.markdown("""
+        - Ensure file is valid Excel format (.xlsx/.xls)
+        - Check file isn't corrupted or password-protected
+        - Try re-uploading the file
+        - Verify all required columns exist
+        """)
+    else:
         is_valid, message = validate_dataframe(df)
         
         if not is_valid:
             st.error(f"❌ {message}")
-            st.markdown("### Required Excel Format:")
-            st.markdown("""
-            Your Excel file should contain these columns:
-            - `question_latex`: The question text with LaTeX formatting
-            - `option_1`: Option A
-            - `option_2`: Option B  
-            - `option_3`: Option C
-            - `option_4`: Option D
-            - `correct_answer` (optional): A, B, C, or D
-            """)
+            st.markdown("### Required Columns:")
+            st.code("question_latex, option_1, option_2, option_3, option_4")
         else:
-            st.success(f"✅ Successfully loaded {len(df)} questions")
+            st.success(f"✅ Loaded {len(df)} questions successfully!")
             
-            # Initialize session state for current question and navigator page
+            # Initialize session state
             if 'current_question' not in st.session_state:
                 st.session_state.current_question = 0
             if 'navigator_page' not in st.session_state:
                 st.session_state.navigator_page = 0
             
-            # Question number selector at the top
+            # Navigation system
             st.markdown("### 📋 Question Navigator")
             
-            # Navigator pagination settings
             total_questions = len(df)
-            questions_per_page = 50  # Questions shown per navigator page
-            questions_per_row = 10   # Question buttons per row
+            questions_per_page = 50
+            questions_per_row = 10
             
-            # Calculate total pages for navigator
             total_nav_pages = (total_questions + questions_per_page - 1) // questions_per_page
             
-            # Navigator page controls (only show if more than 50 questions)
+            # Navigator pagination (if needed)
             if total_questions > questions_per_page:
-                nav_col1, nav_col2, nav_col3, nav_col4, nav_col5 = st.columns([1, 1, 2, 1, 1])
+                nav_cols = st.columns([1, 1, 2, 1, 1])
                 
-                with nav_col1:
-                    if st.button("⏪ First Set", disabled=st.session_state.navigator_page == 0, key="nav_first"):
+                with nav_cols[0]:
+                    if st.button("⏪ First Set", disabled=st.session_state.navigator_page == 0):
                         st.session_state.navigator_page = 0
                         st.rerun()
                 
-                with nav_col2:
-                    if st.button("◀️ Prev Set", disabled=st.session_state.navigator_page == 0, key="nav_prev"):
+                with nav_cols[1]:
+                    if st.button("◀️ Prev Set", disabled=st.session_state.navigator_page == 0):
                         st.session_state.navigator_page -= 1
                         st.rerun()
                 
-                with nav_col3:
-                    # Show current navigator page info
+                with nav_cols[2]:
                     start_q = st.session_state.navigator_page * questions_per_page + 1
                     end_q = min((st.session_state.navigator_page + 1) * questions_per_page, total_questions)
-                    st.markdown(f"**Questions {start_q}-{end_q} of {total_questions} | Page {st.session_state.navigator_page + 1}/{total_nav_pages}**")
+                    st.markdown(f"**Questions {start_q}-{end_q} of {total_questions}**")
                 
-                with nav_col4:
-                    if st.button("Next Set ▶️", disabled=st.session_state.navigator_page >= total_nav_pages - 1, key="nav_next"):
+                with nav_cols[3]:
+                    if st.button("Next Set ▶️", disabled=st.session_state.navigator_page >= total_nav_pages - 1):
                         st.session_state.navigator_page += 1
                         st.rerun()
                 
-                with nav_col5:
-                    if st.button("Last Set ⏩", disabled=st.session_state.navigator_page >= total_nav_pages - 1, key="nav_last"):
+                with nav_cols[4]:
+                    if st.button("Last Set ⏩", disabled=st.session_state.navigator_page >= total_nav_pages - 1):
                         st.session_state.navigator_page = total_nav_pages - 1
                         st.rerun()
                 
                 st.markdown("---")
             
-            # Calculate question range for current navigator page
+            # Question number buttons
             start_idx = st.session_state.navigator_page * questions_per_page
             end_idx = min(start_idx + questions_per_page, total_questions)
             
-            # Create clickable question number buttons for current page
             questions_to_show = end_idx - start_idx
             rows_needed = (questions_to_show + questions_per_row - 1) // questions_per_row
             
@@ -207,7 +246,6 @@ if uploaded_file:
                     question_num = question_idx + 1
                     
                     with col:
-                        # Highlight current question
                         if question_idx == st.session_state.current_question:
                             button_label = f"**Q{question_num}**"
                             button_type = "primary"
@@ -221,65 +259,57 @@ if uploaded_file:
             
             st.markdown("---")
             
-            # Navigation controls for current question
-            col1, col2, col3, col4, col5 = st.columns([1, 1, 2, 1, 1])
+            # Main navigation controls
+            nav_cols = st.columns([1, 1, 2, 1, 1])
             
-            with col1:
+            with nav_cols[0]:
                 if st.button("⏮️ First", disabled=st.session_state.current_question == 0):
                     st.session_state.current_question = 0
-                    # Update navigator page if needed
                     st.session_state.navigator_page = 0
                     st.rerun()
             
-            with col2:
+            with nav_cols[1]:
                 if st.button("⬅️ Previous", disabled=st.session_state.current_question == 0):
                     st.session_state.current_question -= 1
-                    # Update navigator page if needed
                     new_page = st.session_state.current_question // questions_per_page
                     if new_page != st.session_state.navigator_page:
                         st.session_state.navigator_page = new_page
                     st.rerun()
             
-            with col3:
-                # Dropdown selector for quick navigation
+            with nav_cols[2]:
                 question_options = [f"Question {i+1}" for i in range(total_questions)]
                 selected_q = st.selectbox(
-                    "Jump to question:",
+                    "Jump to:",
                     question_options,
-                    index=st.session_state.current_question,
-                    key="question_dropdown"
+                    index=st.session_state.current_question
                 )
                 
-                # Update current question if dropdown selection changes
                 new_index = question_options.index(selected_q)
                 if new_index != st.session_state.current_question:
                     st.session_state.current_question = new_index
-                    # Update navigator page if needed
                     new_page = new_index // questions_per_page
                     if new_page != st.session_state.navigator_page:
                         st.session_state.navigator_page = new_page
                     st.rerun()
             
-            with col4:
+            with nav_cols[3]:
                 if st.button("Next ➡️", disabled=st.session_state.current_question >= total_questions - 1):
                     st.session_state.current_question += 1
-                    # Update navigator page if needed
                     new_page = st.session_state.current_question // questions_per_page
                     if new_page != st.session_state.navigator_page:
                         st.session_state.navigator_page = new_page
                     st.rerun()
             
-            with col5:
+            with nav_cols[4]:
                 if st.button("Last ⏭️", disabled=st.session_state.current_question >= total_questions - 1):
                     st.session_state.current_question = total_questions - 1
-                    # Update navigator page if needed
                     st.session_state.navigator_page = total_nav_pages - 1
                     st.rerun()
             
-            # Progress indicator
+            # Progress bar
             progress = (st.session_state.current_question + 1) / total_questions
             st.progress(progress)
-            st.caption(f"Progress: {st.session_state.current_question + 1}/{total_questions} questions ({progress:.1%})")
+            st.caption(f"Progress: {st.session_state.current_question + 1}/{total_questions} ({progress:.1%})")
             
             st.markdown("---")
             
@@ -287,19 +317,8 @@ if uploaded_file:
             if 0 <= st.session_state.current_question < len(df):
                 current_row = df.iloc[st.session_state.current_question]
                 render_question(st.session_state.current_question, current_row)
-            
-
-                
-    except Exception as e:
-        st.error(f"❌ Error reading file: {e}")
-        st.markdown("### Troubleshooting:")
-        st.markdown("""
-        - Make sure your file is a valid Excel (.xlsx or .xls) file
-        - Check that all required columns are present
-        - Ensure the file is not corrupted or password-protected
-        """)
 
-# Add sample data section
+# Sample data section
 with st.expander("📋 Sample Excel Format"):
     sample_data = pd.DataFrame({
         "question_latex": [
@@ -315,11 +334,10 @@ with st.expander("📋 Sample Excel Format"):
     })
     st.dataframe(sample_data)
     
-    # Download sample
     csv = sample_data.to_csv(index=False)
     st.download_button(
         label="📥 Download Sample CSV",
         data=csv,
         file_name="sample_mcq_format.csv",
         mime="text/csv"
-    )
+    )