Update app.py

app.py

@@ -2,6 +2,7 @@ import streamlit as st
 import pandas as pd
 import plotly.figure_factory as ff
 import random
+from datetime import datetime, timedelta
 
 def generate_random_color():
     r = random.randint(0, 255)
@@ -12,7 +13,7 @@ def generate_random_color():
 st.title("Project Schedule/Gantt Chart Generator")
 
 project_name = st.text_input("Project Name:")
-project_duration = st.number_input("Total Project Duration (days):", min_value=1, value=30)
+start_date = st.date_input("Project Start Date:", value=datetime.today())
 num_activities = st.number_input("Number of Activities (5-20):", min_value=5, max_value=20, value=5)
 
 activities = []
@@ -21,8 +22,8 @@ for i in range(num_activities):
     with col1:
         activity_name = st.text_input(f"Activity {i+1} Name:", key=f"name_{i}")
     with col2:
-        activity_duration = st.number_input(f"Activity {i+1} Duration (days):", min_value=1, max_value=project_duration, key=f"duration_{i}")
-    activities.append({"Task": activity_name, "Start": 0, "Finish": activity_duration})
+        activity_duration = st.number_input(f"Activity {i+1} Duration (days):", min_value=1, key=f"duration_{i}")
+    activities.append({"Task": activity_name, "Duration": activity_duration})
 
 if st.button("Create Gantt Chart"):
     if not project_name:
@@ -31,12 +32,19 @@ if st.button("Create Gantt Chart"):
         st.error("Please enter names for all activities.")
     else:
         df = pd.DataFrame(activities)
-        current_finish = 0
+        df['Start'] = pd.to_datetime(start_date)
+        df['Finish'] = df['Start']
         for i in range(len(df)):
-            df.loc[i, "Start"] = current_finish
-            current_finish += df.loc[i, "Finish"]
-            df.loc[i, "Finish"] = current_finish
+            if i > 0:
+                df.loc[i, 'Start'] = df.loc[i-1, 'Finish']
+            df.loc[i, 'Finish'] = df.loc[i, 'Start'] + pd.to_timedelta(df.loc[i, 'Duration'], unit='D')
         
-        fig = ff.create_gantt(df, colors=[generate_random_color() for _ in range(len(df))], index_col='Task', show_colorbar=True, group_tasks=True)
+        df['Start'] = df['Start'].dt.strftime('%Y-%m-%d')
+        df['Finish'] = df['Finish'].dt.strftime('%Y-%m-%d')
+
+        fig = ff.create_gantt(df, colors=[generate_random_color() for _ in range(len(df))],
+                              index_col='Task', show_colorbar=False, group_tasks=True, bar_width=0.4, showgrid_x=True, showgrid_y=True)
         fig.update_layout(title_text=f"Gantt Chart for: {project_name}", title_x=0.5)
+
+        fig.update_yaxes(autorange="reversed")  # To put activities inside graph
         st.plotly_chart(fig, use_container_width=True)