import unittest
import user_code
import ast
import re   
import importlib
import csv
import polars as pl

class TestTask(unittest.TestCase):
    def setUp(self):
        # Initializing local mock dataset using a Polars DataFrame matching the solution schema
        self.df = pl.DataFrame({
            "Publishers": ["Valve", "Valve", "IndieCo", "Valve"],
            "Price": [9.99, 0.0, 4.99, 19.99],
            "Positive": [1000, 500, 100, 2000]
        })

    def test_aggregation_columns_exist(self):
        import user_code
        importlib.reload(user_code)
        func = getattr(user_code, "aggregate_publishers_stats", None)
        _dynamic_test(
            self,
            callable(func),
            "aggregate_publishers_stats function exists and is callable.",
            "aggregate_publishers_stats function is missing or not callable."
        )
        result = func(self.df)
        _dynamic_test(
            self,
            result is not None and "Publishers" in result.columns,
            "Returned DataFrame contains grouping column 'Publishers'.",
            "Returned DataFrame is missing grouping column 'Publishers'."
        )
        _dynamic_test(
            self,
            "Average Price" in result.columns,
            "Returned DataFrame contains 'Average Price' metric column.",
            "Returned DataFrame is missing 'Average Price' metric column."
        )
        _dynamic_test(
            self,
            "Total Positive Reviews" in result.columns,
            "Returned DataFrame contains 'Total Positive Reviews' metric column.",
            "Returned DataFrame is missing 'Total Positive Reviews' metric column."
        )

    def test_aggregation_values_correct(self):
        import user_code
        importlib.reload(user_code)
        func = getattr(user_code, "aggregate_publishers_stats", None)
        result = func(self.df)
        
        if result is not None and "Average Price" in result.columns and "Total Positive Reviews" in result.columns:
            # Extract Valve records for validation
            valve_data = result.filter(pl.col("Publishers") == "Valve")
            
            _dynamic_test(
                self,
                len(valve_data) == 1,
                "Grouping strategy correctly combined duplicate records.",
                f"Expected unique row for 'Valve', found {len(valve_data)} rows."
            )
            
            # Valve math: 
            # Average Price = (9.99 + 0.0 + 19.99) / 3 = 9.99333...
            # Total Positive Reviews = 1000 + 500 + 2000 = 3500
            actual_price = valve_data["Average Price"][0]
            actual_reviews = valve_data["Total Positive Reviews"][0]
            
            _dynamic_test(
                self,
                abs(actual_price - 9.993333) < 1e-4,
                "Mean aggregation engine evaluated correct 'Average Price'.",
                f"Incorrect 'Average Price' calculation. Expected near 9.9933, Got: {actual_price}"
            )
            _dynamic_test(
                self,
                actual_reviews == 3500,
                "Sum aggregation engine evaluated correct 'Total Positive Reviews'.",
                f"Incorrect 'Total Positive Reviews' calculation. Expected 3500, Got: {actual_reviews}"
            )
            
            # IndieCo records validation
            indie_data = result.filter(pl.col("Publishers") == "IndieCo")
            actual_indie_price = indie_data["Average Price"][0]
            actual_indie_reviews = indie_data["Total Positive Reviews"][0]
            
            _dynamic_test(
                self,
                actual_indie_price == 4.99 and actual_indie_reviews == 100,
                "Single-instance group records aggregation validated cleanly.",
                f"Aggregation failed on single items. Got Price: {actual_indie_price}, Reviews: {actual_indie_reviews}"
            )
        else:
            _dynamic_test(self, False, "", "Metrics execution evaluation halted due to missing target columns.")

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

def normalize_text(text):
    text = text.lower()
    text = re.sub(r"\s{2,}", " ", text)
    text = re.sub(r"\s*([,:?])\s*", r"\1 ", text)
    return text.strip()

def change_var(code: str, var_name: str, value: str) -> str:
    tree = ast.parse(code)
    lines = code.splitlines()
    changed = False
    assign_nodes = [
        (i, node)
        for i, node in enumerate(tree.body)
        if isinstance(node, ast.Assign)
        and any(isinstance(target, ast.Name) and target.id == var_name for target in node.targets)
    ]

    if not assign_nodes:
        return code

    for i, node in reversed(assign_nodes):
        start_line = node.lineno - 1
        line = lines[start_line]
        indent = ' ' * (len(line) - len(line.lstrip()))
        lines[start_line] = f"{indent}{var_name} = {value}"
        next_line = len(lines)
        for next_node in tree.body[i+1:]:
            if hasattr(next_node, 'lineno'):
                next_line = next_node.lineno - 1
                break
        if next_line > start_line + 1:
            lines[start_line+1:next_line] = []
        changed = True

    return '\\n'.join(lines) if changed else code

if __name__ == "__main__":
    unittest.main()

test_main.py

Ein praxisorientierter, mittlerer Kurs für Python-Entwickler zur Beherrschung des Data Wrangling mit Polars anhand von realen Steam-Spieldatensätzen. Vermittelt wird das spaltenorientierte Paradigma von Polars, Selektion, Aggregation, Verknüpfung, Umformung sowie grundlegende Operationen mit Zeichenketten, Datumswerten und fehlenden Daten.

Untersuchung der grundlegenden Unterschiede zwischen Polars und traditionellen zeilenbasierten DataFrames mit Schwerpunkt auf spaltenbasierten Operationen, Selektion und bedingter Logik anhand des Steam-Games-Datensatzes.

Erwerben Sie ein fundiertes Verständnis der parallelen Group-by-, Aggregations-, Join- und Umformungsfunktionen von Polars anhand der Steam-Spiele- und Spy-Insights-Datensätze.

Erkunden Sie die Grundlagen der Datenbereinigung: Textnormalisierung, Datumsanalyse und robuste Behandlung fehlender Werte in Polars.

Herausforderung: Group_by & Aggregationen

Lösung