How to return a dictionary | Python

What's going on is that you're returning right after the first line of the file doesn't match the id you're looking for. You have to do this:

def query(id):
    for line in file:
        table = {}
        (table["ID"],table["name"],table["city"]) = line.split(";")
        if id == int(table["ID"]):
             file.close()
             return table
    # ID not found; close file and return empty dict
    file.close()
    return {}


def query(id):
    for line in file:
        table = line.split(";")
        if id == int(table[0]):
             yield table
    
    

id = int(input("Enter the ID of the user: "))
for id_, name, city in query(id):
  print("ID: " + id_)
  print("Name: " + name)
  print("City: " + city)
file.close()

Using yield..