Server-side vs Client-side/Local Objects

Server-side¶

stored on GEE’s servers (not on your local machine)
any variable created with ee.* is a server-side object
can’t be used directly with non-ee.* variables or functions

Client-side or local¶

stored in your local machine
regular Python variable

import ee

# Trigger the authentication flow.
ee.Authenticate()

# Initialize the library.
ee.Initialize(project='your-gee-project-id-here') #replace your-gee-project w/ your actual GEE project name

# Define some local (client-side) variables
local_num1 = 100
local_num2 = 200

# Define some server-side (ee.*) variables with the same value
server_num1 = ee.Number(local_num1)
server_num2 = ee.Number(local_num2)

# Get the sum of the local variables then display it
local_sum = local_num1 + local_num2
print(local_sum)
print(type(local_sum))

300
<class 'int'>

⚠️ CAUTION

It is usually not recommended to mix client-side (local) and server-side objects and methods.

👨‍💻 TRY IT OUT

Get the sum of the server variables then display it

# Try your solution here

💡 TIP

When working with server-side objects or variables, you should also use server-side (ee.*) functions.
When in doubt, refer to the GEE API Documentation.

# Checking what class the server-side variables are may give us an idea
print(type(server_num1))

# Use the add method of the ee.Number class (https://developers.google.com/earth-engine/apidocs/ee-number-add)
server_sum = server_num1.add(server_num2)

# Use .getInfo()
print(server_sum.getInfo())
print(type(server_sum.getInfo()))

ee.Number({
  "functionInvocationValue": {
    "functionName": "Number.add",
    "arguments": {
      "left": {
        "constantValue": 100
      },
      "right": {
        "constantValue": 200
      }
    }
  }
})
<class 'ee.ee_number.Number'>

🤔 SOMETHING TO THINK ABOUT

Did you notice any differences between the server-side and client/local computation of the sum?