Python alternative for ArcPy's Con tool?

Question

I'm wondering if there is a method to perform a function similar to ArcGIS's Con tool, using open source options in Python.

I have two rasters, one that shows veloticty and one that shows detph. With ArcPy it is easy to get a new raster:

Con(((detph >= 1) | (veloticty >= 1)|(detph*veloticty>=0.5)), 3,(Con(((detph >= 0.4) | (veloticty >= 0.4)|(detph*veloticty>=0.08)), 2,1)))

I would like to do with open source options in Python.

Answer 1

Try reading the rasters into numpy arrays using rasterio, numpy where instead of Con and then write the output as raster.

import numpy as np
import rasterio

demfile = '/home/bera/GIS/DEM50m/nh_68_4.tif'

dem = rasterio.open(demfile)
demarr = dem.read()
onezero = np.random.randint(2, size=demarr.shape)

newarr = np.where(onezero==1, demarr, np.where(demarr>500, 1000, 0))
newarr = newarr.astype('float32')

with rasterio.Env():
    profile = dem.profile
    with rasterio.open('/home/bera/Desktop/tempgis/dem_modified.tif', 'w', **profile) as dst:
        dst.write(newarr)