Define points within a polygon

Question

I have a list of customers lat and long and I want to define which ones are within a given polygon. But the results I got are none of them in that polygon and it is not correct.

Could you please help? Thanks!

from shapely.geometry import Polygon
from shapely.geometry import Point
import pandas as pd
import geopandas as gpd
df=pd.read_csv("C:\\Users\\n.nguyen.2\\Documents\\order from May 1.csv")

geometry=[Point(xy) for xy in zip(df['customer_lat'],df['customer_lng'])]
crs={'init':'epsg:4326'}
gdf=gpd.GeoDataFrame(df,crs=crs,geometry=geometry)
gdf.head()

polygon= Polygon ([(103.85362669999994, 1.4090082), (103.8477709, 1.4051988), (103.84821190000002, 1.4029509), (103.84933950000004, 1.4012179), (103.85182859999998, 1.4001453), (103.85393150000004, 1.3986867), (103.85745050000001, 1.3962412), (103.85809410000002, 1.3925516), (103.85843750000004, 1.3901491), (103.8583946, 1.3870601), (103.8585663, 1.3838853), (103.8582659, 1.3812682), (103.85822299999997, 1.3792946), (103.85843750000004, 1.3777931), (103.85882370000002, 1.3748757), (103.86015410000005, 1.3719582), (103.8607978, 1.3700276), (103.86092659999998, 1.368097), (103.86036880000006, 1.3657372), (103.8593174, 1.3633562), (103.85852339999995, 1.3607605), (103.85745050000001, 1.3581005), (103.8571071, 1.355655), (103.85736459999998, 1.3520941), (103.85873790000007, 1.3483615), (103.86187100000006, 1.3456583), (103.86488409999993, 1.340689), (103.87096889999998, 1.3378933), (103.87519599999996, 1.3373354), (103.88178349999998, 1.3408963), (103.88508790000004, 1.3433418), (103.89186870000005, 1.3436426), (103.89742610000008, 1.342355), (103.91813279999997, 1.3805388), (103.91824964404806, 1.3813377489306), (103.91433759243228, 1.38607494841128), (103.91607279999994, 1.3895484), (103.91942029999996, 1.3940104), (103.92903330000001, 1.4009604), (103.9342689, 1.402076), (103.93289559999994, 1.4075675), (103.92534249999994, 1.4146035), (103.92517090000003, 1.4211246), (103.90972139999997, 1.4238704), (103.89942169999993, 1.4202666), (103.89744760000008, 1.4224117), (103.89315599999998, 1.425758), (103.88740540000003, 1.4285896), (103.88148309999995, 1.4328798), (103.87478829999998, 1.4331372), (103.85918850000007, 1.4249644), (103.85401679999995, 1.4114284), (103.85362669999994, 1.4090082)])

gdf['answer']=gdf['geometry'].within(polygon)
writer = pd.ExcelWriter("C:\\Users\\n.nguyen.2\\Documents\\order may define1.xlsx")
gdf.to_excel(writer, 'Sheet1', index=False)
writer.save()

The results are all false.

Raw data:

Result:

Answer 1

Adding my comments as an answer for future reference.

You have switched longitude and latitude in the order of coordinates. Look at coordinates of your polygon and those of points. Coordinates of points you have generated are (Lat, Lon), while your polygon (Lon, Lat). So these points are not within this polygon. Do

geometry=[Point(xy) for xy in zip(df['customer_lng'],df['customer_lat'])] 

instead and it will work.

To make your life easier, geopandas has helper function for creating points from polygons points_from_xy() ( http://geopandas.org/gallery/create_geopandas_from_pandas.html?highlight=points_from_xy )