def test_dynamodb_delete_all_items():
table_name = "awsimple-delete-test" # this test is the only thing we'll use this table for
dynamodb_access = DynamoDBAccess(table_name,
profile_name=test_awsimple_str)
dynamodb_access.create_table(id_str)
dynamodb_access.put_item(dict_to_dynamodb({id_str: "me", "answer": 42}))
dynamodb_access.put_item(dict_to_dynamodb({id_str: "you", "question": 0}))
while len(table_contents := dynamodb_access.scan_table()) != 2:
print(f"waiting for the put ...{table_contents}")
time.sleep(1) # DynamoDB is "eventually consistent"
def test_dynamodb_delete():
dynamodb_access = DynamoDBAccess(profile_name=test_awsimple_str,
table_name=test_awsimple_str)
dynamodb_access.create_table(id_str)
test_id = "deleter"
item_value = {id_str: test_id, "color": "blue"}
dynamodb_access.put_item(item_value)
assert dynamodb_access.get_item(
id_str, test_id) == item_value # check that it's set
dynamodb_access.delete_item(id_str, test_id)
with pytest.raises(DBItemNotFound):
print(dynamodb_access.get_item(id_str,
test_id)) # check that it's deleted
def test_dynamodb():
dynamodb_dict = dict_to_dynamodb(sample_input)
assert dynamodb_dict["sample1"] == "Test Data"
assert math.isclose(float(dynamodb_dict["sample2"]), decimal.Decimal(2.0))
assert dynamodb_dict["sample3"] is True
assert dynamodb_dict["sample5"] is None
assert dynamodb_dict["sample6"] == {"test": True}
assert dynamodb_dict["sample7"] == ["Hello", "World"]
assert dynamodb_dict["sample8"] == [
decimal.Decimal(9), decimal.Decimal(10)
]
assert dynamodb_dict["DecimalInt"] == decimal.Decimal(42)
assert dynamodb_dict["DecimalFloat"] == decimal.Decimal(
2.0) / decimal.Decimal(3.0)
assert dynamodb_dict["a_tuple"] == [1, 2, 3]
assert dynamodb_dict[
"42"] == "my_key_is_an_int" # test conversion of an int key to a string
assert dynamodb_dict["test_date_time"] == "2019-06-04T20:18:55+00:00"
assert dynamodb_dict["zero_len_string"] is None
# while dictim is case insensitive, when we convert to dict for DynamoDB it becomes case sensitive
assert list(dynamodb_dict["dictim"]["HI"])[0] == "there"
assert dynamodb_dict["dictim"]["HI"]["there"] == 1 # actually Decimal(1)
assert dynamodb_dict["dictim"].get(
"hi") is None # we're back to case sensitivity
dynamodb_access = DynamoDBAccess(
profile_name=test_awsimple_str,
table_name=test_awsimple_str,
cache_dir=Path("cache"),
cache_life=timedelta(seconds=1).total_seconds())
dynamodb_access.create_table(id_str)
dynamodb_access.put_item(dynamodb_dict)
sample_from_db = dynamodb_access.get_item(id_str, dict_id)
assert sample_from_db == dynamodb_dict # make sure we get back exactly what we wrote
table_contents = dynamodb_access.scan_table_cached()
assert not dynamodb_access.cache_hit
check_table_contents(table_contents)
table_contents = dynamodb_access.scan_table()
check_table_contents(table_contents)
table_contents = dynamodb_access.scan_table_cached()
assert dynamodb_access.cache_hit
check_table_contents(table_contents)
assert dynamodb_access.get_primary_keys() == (id_str, None) # no sort key
def test_dynamodb_sort_as_number():
dynamodb_access = DynamoDBAccess(
profile_name=test_awsimple_str,
table_name=f"{test_awsimple_str}_sort_as_number",
cache_dir=Path("cache"))
dynamodb_access.create_table("id", "year",
sort_key_type=int) # sort key as number
input_item = {"id": "me", "year": 1999, "out_of_time": False}
dynamodb_access.put_item(input_item)
item = dynamodb_access.get_item("id", "me", "year", 1999)
output_item = dynamodb_to_dict(item)
pprint(item)
assert input_item == output_item
dynamodb_access.delete_table()
def test_dynamodb_secondary_index():
table_name = f"{test_awsimple_str}2"
table = DynamoDBAccess(table_name)
sort_key = "id2"
secondary_index = "id3"
table.create_table(id_str, sort_key, secondary_index)
item = {id_str: "me", sort_key: "myself", secondary_index: "i"}
table.put_item(item)
item2 = deepcopy(item)
item2[sort_key] = "moi même" # also test unicode!
item2[secondary_index] = "je"
table.put_item(item2)
query_results = table.query(id_str, "me")
print(f"{query_results=}")
assert len(
query_results
) == 2 # just the partition key should provide us with both rows
assert table.query(secondary_index, "je") == [
item2
] # with (only) the secondary index (in DynamoDB you can't mix primary and secondary indexes)
expected_contents = {
DictKey(partition="me", sort="moi même"): {
"id": "me",
"id2": "moi même",
"id3": "je"
},
DictKey(partition="me", sort="myself"): {
"id": "me",
"id2": "myself",
"id3": "i"
},
}
contents = table.scan_table_cached_as_dict()
assert contents == expected_contents
assert list(contents.keys()) == [
DictKey(partition="me", sort="moi même"),
DictKey(partition="me", sort="myself")
]
table.delete_table()
def test_dynamodb_partition_as_number():
dynamodb_access = DynamoDBAccess(
profile_name=test_awsimple_str,
table_name=f"{test_awsimple_str}_partition_as_number",
cache_dir=Path("cache"))
dynamodb_access.create_table(
"year", "id", partition_key_type=int) # partition key as number
input_item = {"id": "me", "year": 1999, "out_of_time": False}
dynamodb_access.put_item(input_item)
item = dynamodb_access.get_item("id", "me", "year", 1999)
pprint(item)
assert input_item == dynamodb_to_dict(item)
item = dynamodb_access.query(
"year", 1999)[0] # only use the partition key (no sort key)
pprint(item)
assert input_item == dynamodb_to_dict(item)
dynamodb_access.delete_table()
def test_dynamodb_secondary_index_int():
table_name = f"{test_awsimple_str}3"
table = DynamoDBAccess(table_name)
sort_key = "id2"
secondary_index = "num"
table.create_table(id_str,
sort_key,
secondary_index,
secondary_key_type=int) # secondary index as an int
table.put_item({id_str: "me", sort_key: "myself", secondary_index: 1})
table.put_item({id_str: "me", sort_key: "moi", secondary_index: 2})
query_results = table.query(id_str, "me")
print(f"{query_results=}")
assert len(
query_results
) == 2 # just the partition key should provide us with both rows
table.delete_table()
def test_dynamodb_scan_table_as_dict():
dynamodb_access = DynamoDBAccess(profile_name=test_awsimple_str, table_name=test_awsimple_str, cache_dir=Path("cache"), cache_life=timedelta(seconds=10).total_seconds())
dynamodb_access.create_table(id_str)
dynamodb_access.put_item({id_str: "b", "value": 1}) # will be sorted in a different order than we're inputting
dynamodb_access.put_item({id_str: "c", "value": 3})
dynamodb_access.put_item({id_str: "a", "value": 2})
expected_contents = {"a": {"id": "a", "value": Decimal("2")}, "b": {"id": "b", "value": Decimal("1")}, "c": {"id": "c", "value": Decimal("3")}}
table_contents = dynamodb_access.scan_table_as_dict()
check_scan_table(table_contents, expected_contents)
table_contents = dynamodb_access.scan_table_cached_as_dict()
check_scan_table(table_contents, expected_contents)
table_contents = dynamodb_access.scan_table_cached_as_dict()
assert dynamodb_access.cache_hit
check_scan_table(table_contents, expected_contents)
table_contents = dynamodb_access.scan_table_cached_as_dict(sort_key=lambda x: x[id_str]) # test sort_key
check_scan_table(table_contents, expected_contents)
def test_dynamodb_query():
table_name = "testawsimpleps" # ps = both partition and sort
dynamodb_access = DynamoDBAccess(profile_name=test_awsimple_str,
table_name=table_name)
dynamodb_access.create_table("id", "name")
# three entries for "me"
dynamodb_access.put_item({
"id": "me",
"name": "james",
"answer": 13
}) # this will be the "first" one
dynamodb_access.put_item({"id": "me", "name": "james abel", "answer": 1})
dynamodb_access.put_item({
"id": "me",
"name": "zzz",
"answer": 99
}) # this will be the "last" one
dynamodb_access.put_item({"id": "notme", "name": "notjames", "answer": 42})
response = dynamodb_access.query("id", "me") # partition only
assert len(response) == 3
response = dynamodb_access.query("id", "me", "name",
"james") # partition and sort
assert len(response) == 1
response = dynamodb_access.query_begins_with("id", "me", "name",
"james a") # begins with
assert len(response) == 1
response = dynamodb_access.query_begins_with("id", "me", "name", "jame")
assert len(response) == 2
response = dynamodb_access.query("id", "idonotexist") # does not exist
assert len(response) == 0
response = dynamodb_access.query_one("id", "me", QuerySelection.highest)
assert response["answer"] == 99
assert response["name"] == "zzz" # the "last" entry, as sorted by sort key
response = dynamodb_access.query_one("id", "me", QuerySelection.lowest)
assert response["answer"] == 13
assert response[
"name"] == "james" # the "first" entry, as sorted by sort key
response = dynamodb_access.query_one("id", "idonotexist",
QuerySelection.lowest)
assert response is None
def test_dynamodb_create_table():
table_name = f"{test_awsimple_str}temp"
dynamodb_access = DynamoDBAccess(table_name,
profile_name=test_awsimple_str)
dynamodb_access.create_table("id")
assert dynamodb_access.table_exists(
) # create_table has a waiter so the table should exist at this point
dynamodb_access.put_item({"id": "me", "value": 1})
table_data = dynamodb_access.scan_table_cached()
pprint(table_data)
assert table_data[0]["id"] == "me"
assert table_data[0]["value"] == 1
assert len(table_data) == 1
assert len(dynamodb_access.scan_table_cached(invalidate_cache=True)) == 1
dynamodb_access.delete_table()
assert not dynamodb_access.delete_table(
) # delete_table has a waiter so the table should exist at this point
def users_example():
"""
This example shows how to use DynamoDB to keep a table of users. This also illustrates the flexibility of NoSQL in that we can
simply add fields at any time.
"""
dynamodb_access = DynamoDBAccess("users_example",
profile_name="testawsimple")
# we're only using email as a partition key in our primary key (no sort key). emails are unique to each user.
dynamodb_access.create_table("email")
# add our first user using email, first and last name. Initially, we may think that's all we need.
dynamodb_access.put_item({
"email": "*****@*****.**",
"first_name": "Victor",
"last_name": "Wooten"
})
# oh no. No one knows who "John Jones" is, they only know "John Paul Jones", so we need to add a middle name.
# Luckily we are using a NoSQL database, so we just add "middle_name" in a new key/value pair. No database migration needed.
dynamodb_access.put_item({
"email": "*****@*****.**",
"first_name": "John",
"middle_name": "Paul",
"last_name": "Jones"
})
# oh no again. No one knows who "Gordon Matthew Thomas Sumner" is either, even with 2 middle names! All they know is "Sting".
# We need to add a nickname. No problem since we're using a NoSQL database.
dynamodb_access.put_item({
"email": "*****@*****.**",
"first_name": "Gordon",
"middle_name": "Matthew",
"middle_name_2": "Thomas",
"last_name": "Sumner",
"nickname": "Sting",
})
# look up user info for one of our users
start = time.time()
item = dynamodb_access.get_item(
"email", "*****@*****.**"
) # this is a "get" since we're using a key and will always get back exactly one item
end = time.time()
pprint(item)
print(
f"took {end-start} seconds"
) # should take just a fraction of a second. 0.05 seconds was a nominal value on our test system.
def musical_instruments_example():
"""
This example shows how to use DynamoDB to keep a table of musical instruments.
"""
dynamodb_access = DynamoDBAccess("musical_instruments_example", profile_name="testawsimple", cache_life=60) # short cache life for development
# Our primary key is a composite of partition (manufacturer) and sort (serial_number).
# For a particular manufacturer, serial numbers define exactly one instrument (for this example we are assuming a serial number can be represented as an
# integer and doesn't have to be a string).
dynamodb_access.create_table("manufacturer", "serial_number", sort_key_type=int)
# we have to convert float to a Decimal for DynamoDB
dynamodb_access.put_item(dict_to_dynamodb({"manufacturer": "Gibson", "serial_number": 1234, "model": "Ripper", "year": 1983, "price": 1299.50}))
dynamodb_access.put_item(dict_to_dynamodb({"manufacturer": "Gibson", "serial_number": 5678, "model": "Thunderbird", "year": 1977, "price": 2399.50}))
dynamodb_access.put_item(
dict_to_dynamodb(
{
"manufacturer": "Fender",
"serial_number": 1234,
"model": "Precision",
"year": 2008,
"price": 1800.0,
} # same serial number as the Gibson Ripper, but that's OK since this is Fender
)
)
# get all the Gibson instruments
start = time.time()
item = dynamodb_access.query("manufacturer", "Gibson") # this can (and will in this case) be multiple items
end = time.time()
pprint(item)
print(f"query took {end-start} seconds") # nominal 0.1 to 0.15 seconds
print()
# get the entire inventory
start = time.time()
all_items = dynamodb_access.scan_table_cached() # use cached if the table is large and *only* if we know our table is slowly or never changing
end = time.time()
pprint(all_items)
print(f"scan took {end-start} seconds ({dynamodb_access.cache_hit=})") # always fast for this small data set, but caching can offer a speedup for large tables