
For at styrke dine færdigheder med gruppering og kvantifikatorer i regulære udtryk skal du nu skrive en funktion, der udtrækker datoer fra tekst. Målet er at identificere datoer i formaterne **"YYYY-MM-DD"** (såsom `2024-06-15`) og **"DD/MM/YYYY"** (såsom `15/06/2024`). Din funktion skal gennemgå en streng og returnere alle matchende datoer i en liste. Denne øvelse hjælper dig med at øve brugen af **grupper**, **kvantifikatorer** og **alternation** til pålideligt at matche flere datoformater.


import unittest
import user_code
import ast
import re   
import unittest
import importlib
import io
from contextlib import redirect_stdout

class TestTask(unittest.TestCase):
    def test_example_output(self):
        import user_code

        importlib.reload(user_code)
        text = "The events are on 2024-06-15 and 15/06/2024."
        result = user_code.extract_dates(text)
        expected = ["2024-06-15", "15/06/2024"]
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Function returns correct list for mixed formats.",
            f"Expected {expected}, got {result}",
        )

    def test_multiple_dates(self):
        import user_code
        importlib.reload(user_code)
        text = "Dates: 2022-01-01, 31/12/2023, and 2020-05-10."
        result = user_code.extract_dates(text)
        expected = ["2022-01-01", "31/12/2023", "2020-05-10"]
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Function finds multiple dates in both formats.",
            f"Expected {expected}, got {result}",
        )

    def test_no_dates(self):
        import user_code
        importlib.reload(user_code)
        text = "There are no dates here."
        result = user_code.extract_dates(text)
        expected = []
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Function returns empty list when no dates present.",
            f"Expected {expected}, got {result}",
        )

    # def test_edge_cases(self):
    #     import user_code
    #     importlib.reload(user_code)
    #     text = "Start:2021-12-31End:01/01/2022More:2022-02-02!"
    #     result = user_code.extract_dates(text)
    #     expected = ["2021-12-31", "01/01/2022", "2022-02-02"]
    #     _dynamic_test(
    #         self,
    #         isinstance(result, list) and result == expected,
    #         "Function finds dates at string edges and with punctuation.",
    #         f"Expected {expected}, got {result}",
    #    )

    def test_invalid_dates(self):
        import user_code
        importlib.reload(user_code)
        text = "These are not dates: 2024-6-15, 5/6/2024, 20240615, 15-06-2024."
        result = user_code.extract_dates(text)
        expected = []
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Function does not match invalid date formats.",
            f"Expected {expected}, got {result}",
        )

    def test_overlapping_dates(self):
        import user_code
        importlib.reload(user_code)
        text = "2023-12-24/2023-12-25 and 24/12/2023/25/12/2023"
        result = user_code.extract_dates(text)
        expected = ["2023-12-24", "2023-12-25", "24/12/2023", "25/12/2023"]
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Function finds adjacent and overlapping dates.",
            f"Expected {expected}, got {result}",
        )

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()
    for i, node in enumerate(tree.body):
        if isinstance(node, ast.Assign):
            for target in node.targets:
                if isinstance(target, ast.Name) and target.id == var_name:
                    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] = []
                    
                    return '\\n'.join(lines)
    return code

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


test_main.py

Et omfattende kursus om Python regulære udtryk, designet til elever med grundlæggende Python-kendskab. Dette kursus dækker regex-syntaks, mønstergenkendelse, avancerede funktioner og praktiske anvendelser gennem teori og praktiske opgaver.

Lær grundlæggende om regulære udtryk i Python, herunder basal syntaks, mønstergenkendelse og essentielle regex-funktioner.

Dyk dybere ned i regex med gruppering, kvantifikatorer, ankre og substitutionsmetoder.

Behersk avancerede regex-funktioner såsom lookahead/lookbehind, ikke-grådig matching, og anvend regex på tekstbehandlingsproblemer fra den virkelige verden.

Challenge: Udtræk Datoer i Forskellige Formater

Challenge: Udtræk Datoer i Forskellige Formater

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