my first phonebook project

import os
def add_details():
    entry=[]
    name=str(input("enter name"))
    no=str(input("enter contact no"))
    entry.append(name)
    entry.append(no)
    return entry
def file(list):
    f=open("phonecontact","a")
    f.write(list[0][0])
    f.write(" : ")
    f.write(list[0][1])
    f.write("\n")
    f.close()
def display():
    if os.path.isfile("phonecontact")==0:
        print("sorry you don't have any phonecontact")
        print("please create it")
    elif os.stat("phonecontact").st_size==0:
        print("phone contact is empty")
    else:
        o=open("phonecontact","r")
        f=o.read()
        print(f)
        o.close()
def search():
    name=input("enter name")
    f=open("phonecontact","r")
    for line in f:
        if name in line:
            print("name is found in phonebook")
            print(line)
            found=True
            break
        else:
            found=False
    if found==False:
        print("name is not found")
def choice():
    print(" enter 1 to add new conact in phonebook")
    print("enter 2 to save conact in file")
    print("enter 3 to to print phonebook file")
    print("enter 4 to search contact from phonebook")
    print("enter 5 to exit from menue")
    c=int(input("enter choice"))
    return c
if os.path.isfile("phonecontact")==0:
    print("sorry you dont have any contact in your phonebook")
    print("please first create it")
    directory=[]
elif os.path.getsize("phonecontact")==0:
    print("your phonebook exists but does not contain any contact,please add some contact")
    directory=[]
else:
    print("you have already some contacys in your phonebook")
    print("you can see it")
    directory=[]
    f=open("phonecontact","r")
    tx=f.read()
    print(tx)
c=True
while c:
    ch=choice()
    if ch==1:
        directory=[]
        e=add_details()
        directory.append(e)
    if ch==2:
        file(directory)
        print("data saved successfully")
        del(directory)
    if ch==3:
        display()
    if ch==4:
        search()
    if ch==5:
        print("thankyou for using my application")
        c=False