deleting select items from a list

[DeaD_EyE]

In my opinion, the list-comprehension is the cleanest solution.
If you have many conditions to fulfill, you can create a function which does the job for you.

def even(user):
    """
    True if uid is even

    This function could check more.
    Just a silly example
    """
    return user["uid"] % 2 == 0


# already existing data
data = [{"uid": num, "name": f"user_{num}"} for num in range(1, 101)]

# later the new list is assigned to the name data
data = [user for user in data if even(user)]

If you work inside a function and want to assign the new list, this will need the use of global, if the list is defined outside the function. This is not very nice. A class can solve this problem of reassigning without the use of global.

class Something:
    def __init__(self):
        self.database = [{"uid": num, "name": f"user_{num}"} for num in range(1, 101)]

    def add_user(self, uid, name):
        self.database.append({"uid": uid, "name": name})

    def delete_odd_users(self):
        self.database = [user for user in self.database if self.is_even(user)]

    def is_even(self, user):
        return user["uid"] % 2 == 0

If you're using threads, you should better use locking to prevent race conditions.