Python3 で Google Datastore のデータを更新 (Update)

Google Datastore にある次のデータを更新する方法です。

datastore_update.py

#! /usr/bin/python
#
#   datastore_update.py
#                       May/18/2018
# ------------------------------------------------------------------
from gcloud import datastore
import sys
import datetime
# ------------------------------------------------------------------
def add_data_proc(client,name,name_city,population):
    sys.stderr.write("name = " + name + "\n")
    kind = 'Cities'
    key = client.key(kind,name)

    task = datastore.Entity(key)

    task.update({
        'population': population,
        'name_city': name_city,
        'date_mod': datetime.datetime.utcnow()
        })

    client.put(task)

    return task.key

# ------------------------------------------------------------------
def name_city_read_proc(client,name):
    kind = 'Cities'
    key = client.key(kind,name)
    results = client.get(key)
#
    return results['name_city']
# ------------------------------------------------------------------
sys.stderr.write("*** start ***\n")
key_in = sys.argv[1]
population_in = int(sys.argv[2])
#
print("%s\t%d" % (key_in, population_in))

try:
    project_id = "my-project-aug-29-2016"
    client = datastore.Client(project_id)
except Exception as ee:
    sys.stderr.write("*** error *** in datastore.Client ***\n")
    sys.stderr.write(str(ee) + "\n")
#
name_city = name_city_read_proc(client,key_in)
add_data_proc(client,key_in,name_city,population_in)
#
sys.stderr.write("*** end ***\n")
#
# ------------------------------------------------------------------

実行コマンド

export GOOGLE_APPLICATION_CREDENTIALS="/home/uchida/my_project_Aug-29-2016-7313bb6c3526.json"
#
./datastore_update.py t0922 98912355