graphPaname/app/preprocessing.py

from folium import Map, Marker, PolyLine
from pandas import DataFrame, json_normalize

from app.data_request import request_dataset
from constants import COLUMNS, COORDINATES


def create_dataframe(dataset) -> DataFrame:
    """
    Creates a DataFrame from a JSON response
    """
    json = request_dataset(dataset)
    df = json_normalize(data=json, record_path=["records"], errors="ignore",)
    filtered_df = df.filter(items=COLUMNS[dataset])
    return filtered_df


def reverse_coordinates(row):
    """
    Reverses each tuples coordinates to ensure folium can parse them correctly
    """
    coord = [tuple(reversed(t)) for t in row["fields.geo_shape.coordinates"]]
    return coord


def create_map(df):
    """
    Creates a Map with markers or lines from the DataFrame
    """
    m = Map(location=COORDINATES, zoom_start=12, tiles="Stamen Terrain")
    for index, row in df.iterrows():
        if row["fields.geo_shape.type"] == "LineString":
            coord = reverse_coordinates(row["fields.geo_shape.coordinates"])
            PolyLine(locations=coord, color="blue", opacity=0.5).add_to(m)
        else:
            lng, lat = row["fields.geo_shape.coordinates"]
            Marker(location=[lat, lng]).add_to(m)
    m.save("app/templates/map.html")