app.py

import streamlit as st

#Globals
if "legal_numbers" not in st.session_state:
    st.session_state.legal_numbers = [1,2,3,4,5,6,7,8,9]
if "gridNumbers" not in st.session_state:
    st.session_state.gridNumbers = ["...", "...", "...", "...", "...", "...", "...", "...", "..."]
if "Value" not in st.session_state:
    st.session_state.Value = "X"
    

def get_userInput(): 
    input = st.text_input("Enter a number between 1 to 9 to mark " + st.session_state.Value, key="input")
    return input

def validate_userInput(user_input):
    if user_input.isdigit():
        if int(user_input) < 1 or int(user_input) > 9:                
            return False
        else: 
            if int(user_input) in st.session_state.legal_numbers:
                return True
            else:
                return False
    else:
        return False

def error_Message(msg):
    st.write(msg)

def toggleValue():
    if st.session_state.Value == "X":
        st.session_state.Value = "O"
    else:
        st.session_state.Value = "X"

def display_guide():
    st.text("How to play: Enter the grid number as shown below to mark 'X' or 'O'. \n"+
    "Kindly pick any number shown in Legal Numbers. \n" +
    "Number cannot be repeated more than twice.")
    
    col1, col2, col3 = st.columns(3)
    col4, col5, col6 = st.columns(3)
    col7, col8, col9 = st.columns(3)    
    with col1:
        st.text("1")
    with col2:
        st.text("2")
    with col3:
        st.text("3")
    with col4:
        st.text("4")
    with col5:
        st.text("5")
    with col6:
        st.text("6")
    with col7:
        st.text("7")
    with col8:
        st.text("8")
    with col9:
        st.text("9")

def display_board(num):  
    col1, col2, col3 = st.columns(3)
    col4, col5, col6 = st.columns(3)
    col7, col8, col9 = st.columns(3)
    st.session_state.gridNumbers[int(num)-1]= st.session_state.Value    
    with col1:
        st.text(st.session_state.gridNumbers[0])
    with col2:
        st.text(st.session_state.gridNumbers[1])
    with col3:
        st.text(st.session_state.gridNumbers[2])
    with col4:
        st.text(st.session_state.gridNumbers[3])
    with col5:
        st.text(st.session_state.gridNumbers[4])
    with col6:
        st.text(st.session_state.gridNumbers[5])
    with col7:
        st.text(st.session_state.gridNumbers[6])
    with col8:
        st.text(st.session_state.gridNumbers[7])
    with col9:
        st.text(st.session_state.gridNumbers[8])
    toggleValue()

def reset_game():
    st.session_state.legal_numbers = [1,2,3,4,5,6,7,8,9]
    st.session_state.gridNumbers = ["...", "...", "...", "...", "...", "...", "...", "...", "..."]
    st.session_state.Value = "X"
    
def update_legalNumbers(number):
    st.session_state.legal_numbers.remove(int(user_input))
    st.text("Legal Numbers: " + "".join(str(st.session_state.legal_numbers)))

#UIApp starts here
st.set_page_config(page_title="Python - Tic Tac Toe", page_icon=":python:")
st.header("Python - Tic Tac Toe")
display_guide()

user_input=get_userInput()
display_board()

#UI Buttons
submit=st.button('Submit')
replay=st.button('Replay')

#Button functionality
if submit:
    response=validate_userInput(user_input)
    if response:
        update_legalNumbers(user_input)
        display_board(user_input)
    else:
         error_Message("Please enter a digit between 1 to 9.")

if replay:
    reset_game()