When deploying a simple API written in Python and Flask, I encountered a strange error: "TypeError: 'float' object is not callable". Even though the variable type was expected to be int, this error appeared. Forcing the variable type to int did not resolve the issue.

Solution

This error is often caused by assigning a float value to a variable that is later used as a callable, such as the range() functon. To fix it, ensure that the variable is declared as an integer, for example:

if lng is not None and lat is not None:
    radius = int(0.1)  # Explicitly cast to int

Additionally, there are other issues in the code:

1. Assigning float to int variables: Parameters like price_min were being read as float, but later used in a context expecting int. Change the type parameter to int:

   price_min = request.args.get('price_min', default=None, type=int)
   price_max = request.args.get('price_max', default=None, type=int)
   rooms_min = request.args.get('rooms_min', default=None, type=int)
   rooms_max = request.args.get('rooms_max', default=None, type=int)
   

2. Using integer variables in string concatenation with out conversion: The code concatenated an integer to a query string without proper conversion. This was fixed, but note that str(str(counter + 6)) is redundant; use str(counter + 6) instead.

After these corrections, the code should work without the "TypeError: 'float' object is not callable" error.

Corrected Code Example

def closest_point():
    lng = request.args.get('lng', default=None, type=float)
    lat = request.args.get('lat', default=None, type=float)

    price_min = request.args.get('price_min', default=None, type=int)
    price_max = request.args.get('price_max', default=None, type=int)

    rooms_min = request.args.get('rooms_min', default=None, type=int)
    rooms_max = request.args.get('rooms_max', default=None, type=int)

    if lng is not None and lat is not None:
        radius = int(0.1)
        lng_min = lng - radius
        lng_max = lng + radius
        lat_min = lat - radius
        lat_max = lat + radius

        cur = g.db.cursor()
        query = f"""
            SELECT id, link, price, longitude, latitude 
            FROM {DATABASE_TABLE_NAME} 
            WHERE latitude >= {lat_min} AND latitude <= {lat_max} 
              AND longitude >= {lng_min} AND longitude <= {lng_max}
        """

        additional_params_count = 0
        if price_min:
            query += f" AND price >= {price_min}"
            additional_params_count += 1
        # Add more filters as needed
        query += " GROUP BY 1,2,3,4,5"
        for counter in range(additional_params_count):
            query += f",{counter + 6}"
        query += ";"

        cur.execute(query)
        columns = [desc[0] for desc in cur.description]
        rows = cur.fetchall()
        flats_json = [
            {k: str(v) for k, v in zip(columns, row)}
            for row in rows
        ]
        return json.dumps(flats_json)
    else:
        return "One of lng or lat parameters missing"

Note: The code above uses f-strings for clarity, but ensure they are used safely to avoid SQL injection. In production, consider parameterized queries.