Python script for calculating the area of a polygon

Question

I am looking for a python code for this polygon. I need to calculate the area inside this polygon and I am new to programming. (Very new). Can anybody assist me with this? I have to use a python code for this, I cannot use any other means.

Answer 1

Here's an example of how you could get the area using a search cursor:

polygon_layer = "C:\\Polygon.shp"

with arcpy.da.SearchCursor(polygon_layer, ("OID@", "SHAPE@")) as search_cursor:
    for row in search_cursor:
        oid = row[0]
        geometry = row[1]

        print "OID {0}: area is {1}".format(oid, geometry.area)

Answer 2

import os
from osgeo import ogr

daShapefile = r"C:\Users\new1.shp" #path where your shape file is present 

driver = ogr.GetDriverByName('ESRI Shapefile')

dataSource = driver.Open(daShapefile,1) # 0 means read-only. 1 means writeable.

# Check to see if shapefile is found.
if dataSource is None:
    print 'Could not open %s' % (daShapefile)
else:
    print 'Opened %s' % (daShapefile)
    layer = dataSource.GetLayer()
    featureCount = layer.GetFeatureCount()
    print "Number of features in %s: %d" % (os.path.basename(daShapefile),featureCount)
    print "\n"


new_field = ogr.FieldDefn("Area", ogr.OFTReal)
new_field.SetWidth(32)
new_field.SetPrecision(2) #added line to set precision
layer.CreateField(new_field)

for feature in layer:
    geom = feature.GetGeometryRef()
    area = geom.GetArea() 
    print area
    feature.SetField("Area", area)
    layer.SetFeature(feature)

''' this code here finds the area of the polygons present in your shape file and adds a field named "Area" to your database with the value of the area of each polygon

Answer 3

same as the accepted answer but it is a one-liner.

area = arcpy.da.FeatureClassToNumPyArray(polygon_layer, 'SHAPE@AREA')[0][0]

for multiple if you want total area

from arcpy import da total_area = sum(i[0] for i in da.FeatureClassToNumPyArray(water_feature, 'SHAPE@AREA'))