def test_high_cardinality_not_discrete():
vals = 3 * [1, 2, 3] + [4.0, 6.0, 9.0, 9.0]
x = NumberTracker()
for v in vals:
x.track(v)
summary = x.to_summary()
assert not summary.is_discrete
def test_low_cardinality_is_discrete():
vals = 3 * [1, 2, 3] + [4.0, 6.0, 9.0, 9.0]
vals = vals * 10
x = NumberTracker()
for v in vals:
x.track(v)
summary = x.to_summary()
assert summary.is_discrete
def test_int_value_should_not_increase_float_count():
x = NumberTracker()
for v in [10, 11, 12]:
x.track(v)
assert x.ints.count == 3
assert x.floats.count == 0
assert x.variance.stddev() == pytest.approx(1.0, 1e-3)
assert x.theta_sketch.get_result().get_estimate() == pytest.approx(3, 1e-4)
hist = x.histogram
assert hist.get_n() == 3
assert hist.get_max_value() == pytest.approx(12, 1e-4)
assert hist.get_min_value() == pytest.approx(10, 1e-4)
def __init__(self,
name,
number_tracker=None,
string_tracker=None,
schema_tracker=None,
counters=None,
frequent_items=None,
cardinality_tracker=None):
# Handle default values
if counters is None:
counters = CountersTracker()
if number_tracker is None:
number_tracker = NumberTracker()
if string_tracker is None:
string_tracker = StringTracker()
if schema_tracker is None:
schema_tracker = SchemaTracker()
if frequent_items is None:
frequent_items = FrequentItemsSketch()
if cardinality_tracker is None:
cardinality_tracker = HllSketch()
# Assign values
self.column_name = name
self.number_tracker = number_tracker
self.string_tracker = string_tracker
self.schema_tracker = schema_tracker
self.counters = counters
self.frequent_items = frequent_items
self.cardinality_tracker = cardinality_tracker
def test_count_is_correct():
x = NumberTracker()
assert x.count == 0
x.track(None)
assert x.count == 0
for val in [1, 2, 3]:
x.track(val)
assert x.count == 3
for val in [1.0, 2.0]:
x.track(val)
assert x.count == 5
def test_track_floats_ints_unique_in_cardinality_estimate():
vals = [1, 2, 3, 4]
x = NumberTracker()
for val in vals:
x.track(val)
assert x.to_summary().unique_count.estimate == 4
for val in vals:
x.track(float(val))
assert x.to_summary().unique_count.estimate == 8
def test_protobuf_roundtrip():
x0 = NumberTracker()
for v in [10, 11, 13]:
x0.track(v)
msg = x0.to_protobuf()
roundtrip = NumberTracker.from_protobuf(msg)
assert x0.ints.count == roundtrip.ints.count
assert x0.floats.count == roundtrip.floats.count
assert x0.histogram.get_n() == roundtrip.histogram.get_n()
assert x0.histogram.get_min_value() == roundtrip.histogram.get_min_value()
assert x0.histogram.get_max_value() == roundtrip.histogram.get_max_value()
def from_protobuf(message):
"""
Load from a protobuf message
Returns
-------
column_profile : ColumnProfile
"""
return ColumnProfile(
message.name,
counters=CountersTracker.from_protobuf(message.counters),
schema_tracker=SchemaTracker.from_protobuf(message.schema),
number_tracker=NumberTracker.from_protobuf(message.numbers),
string_tracker=StringTracker.from_protobuf(message.strings),
frequent_items=FrequentItemsSketch.from_protobuf(
message.frequent_items),
cardinality_tracker=HllSketch.from_protobuf(
message.cardinality_tracker),
)
def test_merge():
x = NumberTracker()
for v in [10, 11, 13]:
x.track(v)
merged = x.merge(x)
assert merged.ints.count == 6
assert merged.floats.count == 0
assert merged.histogram.get_n() == 6
assert merged.histogram.get_max_value() == 13.0
assert merged.histogram.get_min_value() == 10.0
expected_freq = [
(10, 2, 2, 2),
(11, 2, 2, 2),
(13, 2, 2, 2),
]
compare_frequent_items(expected_freq, merged.frequent_numbers.get_frequent_items())
msg = merged.to_protobuf()
NumberTracker.from_protobuf(msg)
def test_float_after_int_resets_int_tracker():
x = NumberTracker()
x.track(10)
x.track(11)
assert x.ints.count == 2
assert x.floats.count == 0
x.track(12.0)
assert x.ints.count == 0
assert x.floats.count == 3
assert x.variance.stddev() == pytest.approx(1.0, 1e-3)
assert x.histogram.get_n() == 3
assert x.theta_sketch.get_result().get_estimate() == pytest.approx(3, 1e-4)
assert x.histogram.get_max_value() == pytest.approx(12, 1e-4)
assert x.histogram.get_min_value() == pytest.approx(10, 1e-4)
def test_empty_merge_succeeds():
x1 = NumberTracker()
x2 = NumberTracker()
x3 = x1.merge(x2)
assert isinstance(x3, NumberTracker)
def test_one_value_not_discrete():
x = NumberTracker()
x.track(1)
assert not x.to_summary().is_discrete