import streamlit as st

def calculate_gpa(grades, credits):
    total_points = sum(g * c for g, c in zip(grades, credits))
    total_credits = sum(credits)
    return round(total_points / total_credits, 2) if total_credits else 0

# Streamlit UI
st.title("GPA Calculator")

num_courses = st.number_input("Enter number of courses:", min_value=1, step=1)

grades = []
credits = []

for i in range(num_courses):
    col1, col2 = st.columns(2)
    with col1:
        grade = st.selectbox(f"Grade for Course {i+1}", options=["A", "B", "C", "D", "F"], index=0, key=f"grade{i}")
    with col2:
        credit = st.number_input(f"Credit Hours for Course {i+1}", min_value=1, step=1, key=f"credit{i}")
    
    grade_points = {"A": 4.0, "B": 3.0, "C": 2.0, "D": 1.0, "F": 0.0}
    grades.append(grade_points[grade])
    credits.append(credit)

if st.button("Calculate GPA"):
    gpa = calculate_gpa(grades, credits)
    st.success(f"Your GPA is: {gpa}")