Chapter 2 — Practice Spatial Points Lines Polygons cont.

Spatial Points, Lines and Polygons in Python

Objectives for this part:

• Create new spatial objects (points, lines, polygons)
• Assign the correct projection or CRS
• Create points from a table or csv of lat and lon

Creating GeoDataFrame Geometries

# Import necessary modules first
import pandas as pd
import geopandas as gpd
from shapely.geometry import Point, LineString, Polygon
import fiona
import matplotlib.pyplot as plt
plt.style.use('bmh') # better for plotting geometries vs general plots.

First, create an empty GeoDataFrame and create a new column called geometry that will contain our Shapely objects:

# Create an empty geopandas GeoDataFrame
newdata = gpd.GeoDataFrame()
print(newdata)

Empty GeoDataFrame
Columns: []
Index: []

GeoDataFrame Components

• data: a pandas.DataFrame, dictionary, or empty list [] containing an desired attribute data. Use [] if no data is
• crs: Coordinate Reference System of the geometry objects. Can be anything accepted by pyproj.CRS.from_user_input(), such as an authority string (eg “EPSG:4326”) or a WKT string.
• geometry: Column name in a DataFrame to use as geometry or Shapely point, line, or polygon object.