perspective-python 4.4.1

A data visualization and analytics component, especially well-suited for large and/or streaming datasets.
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#  ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
#  ┃ ██████ ██████ ██████       █      █      █      █      █ █▄  ▀███ █       ┃
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#  ┃ █      ██████ █  ▀█▄       █ ██████      █      ███▌▐███ ███████▄ █       ┃
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#  ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
#  ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
#  ┃ This file is part of the Perspective library, distributed under the terms ┃
#  ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
#  ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

import pandas as pd
import numpy as np
from perspective import PerspectiveError
from datetime import date, datetime
from pytest import approx, mark, raises

import perspective as psp

client = psp.Server().new_local_client()
Table = client.table


def date_timestamp(date):
    return int(datetime.combine(date, datetime.min.time()).timestamp()) * 1000


def compare_delta(received, expected):
    """Compare an arrow-serialized row delta by constructing a Table."""
    tbl = Table(received)
    assert tbl.view().to_columns() == expected


class TestView(object):
    def test_view_zero(self):
        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
        tbl = Table(data)
        view = tbl.view()
        tbl2 = Table(view)
        view2 = tbl2.view()
        dimms = view2.dimensions()
        assert dimms["num_view_rows"] == 2
        assert dimms["num_view_columns"] == 2
        assert view2.schema() == {"a": "integer", "b": "integer"}
        assert view2.to_records() == data

    def test_view_one(self):
        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
        tbl = Table(data)
        view = tbl.view(group_by=["a"])
        tbl2 = Table(view)
        view2 = tbl2.view()

        dimms = view2.dimensions()
        assert dimms["num_view_rows"] == 3
        assert dimms["num_view_columns"] == 3
        assert view2.schema() == {
            "a (Group by 1)": "integer",
            "a": "integer",
            "b": "integer",
        }

        assert view2.to_records() == [
            {"a (Group by 1)": None, "a": 4, "b": 6},
            {"a (Group by 1)": 1, "a": 1, "b": 2},
            {"a (Group by 1)": 3, "a": 3, "b": 4},
        ]

    def test_view_two(self):
        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
        tbl = Table(data)
        view = tbl.view(group_by=["a"], split_by=["b"])
        tbl2 = Table(view)
        view2 = tbl2.view()
        dimms = view2.dimensions()
        assert dimms["num_view_rows"] == 3
        assert dimms["num_view_columns"] == 5
        assert view2.schema() == {
            "a (Group by 1)": "integer",
            "2|a": "integer",
            "2|b": "integer",
            "4|a": "integer",
            "4|b": "integer",
        }

        assert view2.to_records() == [
            {
                "a (Group by 1)": None,
                "2|a": 1,
                "2|b": 2,
                "4|a": 3,
                "4|b": 4,
            },
            {
                "a (Group by 1)": 1,
                "2|a": 1,
                "2|b": 2,
                "4|a": None,
                "4|b": None,
            },
            {
                "a (Group by 1)": 3,
                "2|a": None,
                "2|b": None,
                "4|a": 3,
                "4|b": 4,
            },
        ]

    def test_view_two_column_only(self):
        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
        tbl = Table(data)
        view = tbl.view(split_by=["b"])
        tbl2 = Table(view)
        view2 = tbl2.view()
        dimms = view2.dimensions()
        assert dimms["num_view_rows"] == 2
        assert dimms["num_view_columns"] == 4
        assert view2.schema() == {
            "2|a": "integer",
            "2|b": "integer",
            "4|a": "integer",
            "4|b": "integer",
        }

        assert view2.to_records() == [
            {"2|a": 1, "2|b": 2, "4|a": None, "4|b": None},
            {"2|a": None, "2|b": None, "4|a": 3, "4|b": 4},
        ]