{"id":55,"date":"2025-09-24T22:15:00","date_gmt":"2025-09-24T20:15:00","guid":{"rendered":"http:\/\/python-ai.pl\/?p=55"},"modified":"2025-09-24T22:15:00","modified_gmt":"2025-09-24T20:15:00","slug":"praca-z-plikami","status":"publish","type":"post","link":"https:\/\/python-ai.pl\/?p=55","title":{"rendered":"Praca z plikami"},"content":{"rendered":"\n
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Praca z plikami w Pythonie<\/h4>\n\n\n\n

Python oferuje pot\u0119\u017cne narz\u0119dzia do pracy z plikami. Mo\u017cesz czyta\u0107, zapisywa\u0107 i zarz\u0105dza\u0107 r\u00f3\u017cnymi typami plik\u00f3w.<\/p>\n\n\n\n

Podstawowe operacje na plikach:<\/h4>\n\n\n\n

U\u017cywamy funkcji open()<\/code> do otwierania plik\u00f3w:<\/p>\n\n\n\n

<\/path><\/path><\/svg><\/span>
# Otwieranie pliku do odczytu<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"przyklad.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    content = file.read()<\/span><\/span>\n    <\/span>print<\/span>(content)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Tryby otwierania plik\u00f3w:<\/h4>\n\n\n\n
    \n
  • \"r\"<\/code> – odczyt (domy\u015blny)<\/li>\n\n\n\n
  • \"w\"<\/code> – zapis (nadpisuje plik)<\/li>\n\n\n\n
  • \"a\"<\/code> – dopisywanie (dodaje na ko\u0144cu)<\/li>\n\n\n\n
  • \"r+\"<\/code> – odczyt i zapis<\/li>\n\n\n\n
  • \"b\"<\/code> – tryb binarny (np. „rb”, „wb”)<\/li>\n<\/ul>\n\n\n\n
    Zapisywanie do pliku:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    # Zapisywanie tekstu do pliku<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"notatki.txt"<\/span>, <\/span>"w"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    file.write(<\/span>"To jest pierwsza linia<\/span>\\n<\/span>"<\/span>)<\/span><\/span>\n    file.write(<\/span>"To jest druga linia<\/span>\\n<\/span>"<\/span>)<\/span><\/span>\n    file.write(<\/span>"Python jest \u015bwietny!"<\/span>)<\/span><\/span>\n<\/span>\nprint<\/span>(<\/span>"Plik zosta\u0142 zapisany!"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Dodawanie do pliku:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    # Dodawanie tekstu na ko\u0144cu pliku<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"notatki.txt"<\/span>, <\/span>"a"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    file.write(<\/span>"<\/span>\\n<\/span>To jest nowa linia dodana p\u00f3\u017aniej<\/span>\\n<\/span>"<\/span>)<\/span><\/span>\n    file.write(<\/span>"Koniec pliku"<\/span>)<\/span><\/span>\n<\/span>\nprint<\/span>(<\/span>"Tekst zosta\u0142 dodany do pliku!"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    R\u00f3\u017cne sposoby czytania pliku:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    # Czytanie ca\u0142ego pliku jako string<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"przyklad.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    content = file.read()<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"Ca\u0142y plik:"<\/span>)<\/span><\/span>\n    <\/span>print<\/span>(content)<\/span><\/span>\n<\/span>\n# Czytanie linia po linii<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"przyklad.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"<\/span>\\n<\/span>Linia po linii:"<\/span>)<\/span><\/span>\n    <\/span>for<\/span> line <\/span>in<\/span> file:<\/span><\/span>\n        <\/span>print<\/span>(<\/span>f<\/span>"Linia: <\/span>{<\/span>line.strip()<\/span>}<\/span>"<\/span>)<\/span><\/span>\n<\/span>\n# Czytanie wszystkich linii jako lista<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"przyklad.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    lines = file.readlines()<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"<\/span>\\n<\/span>Lista linii:"<\/span>)<\/span><\/span>\n    <\/span>for<\/span> i, line <\/span>in<\/span> <\/span>enumerate<\/span>(lines):<\/span><\/span>\n        <\/span>print<\/span>(<\/span>f<\/span>"Linia <\/span>{<\/span>i+<\/span>1<\/span>}<\/span>: <\/span>{<\/span>line.strip()<\/span>}<\/span>"<\/span>)<\/span><\/span>\n<\/span>\n# Czytanie tylko pierwszej linii<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"przyklad.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    first_line = file.readline()<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"<\/span>\\n<\/span>Pierwsza linia: <\/span>{<\/span>first_line.strip()<\/span>}<\/span>"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Praca z plikami CSV:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    import<\/span> csv<\/span><\/span>\n<\/span>\n# Zapisywanie danych CSV<\/span><\/span>\ndata = [<\/span><\/span>\n    [<\/span>"Imi\u0119"<\/span>, <\/span>"Wiek"<\/span>, <\/span>"Miasto"<\/span>],<\/span><\/span>\n    [<\/span>"Jan"<\/span>, <\/span>"25"<\/span>, <\/span>"Warszawa"<\/span>],<\/span><\/span>\n    [<\/span>"Anna"<\/span>, <\/span>"30"<\/span>, <\/span>"Krak\u00f3w"<\/span>],<\/span><\/span>\n    [<\/span>"Piotr"<\/span>, <\/span>"28"<\/span>, <\/span>"Gda\u0144sk"<\/span>]<\/span><\/span>\n]<\/span><\/span>\n<\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"osoby.csv"<\/span>, <\/span>"w"<\/span>, <\/span>newline<\/span>=<\/span>""<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    writer = csv.writer(file)<\/span><\/span>\n    writer.writerows(data)<\/span><\/span>\n<\/span>\nprint<\/span>(<\/span>"Plik CSV zosta\u0142 utworzony!"<\/span>)<\/span><\/span>\n<\/span>\n# Czytanie danych CSV<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"osoby.csv"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    reader = csv.reader(file)<\/span><\/span>\n    <\/span>for<\/span> row <\/span>in<\/span> reader:<\/span><\/span>\n        <\/span>print<\/span>(<\/span>f<\/span>"Imi\u0119: <\/span>{<\/span>row[<\/span>0<\/span>]<\/span>}<\/span>, Wiek: <\/span>{<\/span>row[<\/span>1<\/span>]<\/span>}<\/span>, Miasto: <\/span>{<\/span>row[<\/span>2<\/span>]<\/span>}<\/span>"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Sprawdzanie istnienia pliku:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    import<\/span> os<\/span><\/span>\n<\/span>\nfilename = <\/span>"przyklad.txt"<\/span><\/span>\n<\/span>\n# Sprawdzanie czy plik istnieje<\/span><\/span>\nif<\/span> os.path.exists(filename):<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Plik <\/span>{<\/span>filename<\/span>}<\/span> istnieje"<\/span>)<\/span><\/span>\n    <\/span><\/span>\n    <\/span># Sprawdzanie rozmiaru pliku<\/span><\/span>\n    size = os.path.getsize(filename)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Rozmiar pliku: <\/span>{<\/span>size<\/span>}<\/span> bajt\u00f3w"<\/span>)<\/span><\/span>\nelse<\/span>:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Plik <\/span>{<\/span>filename<\/span>}<\/span> nie istnieje"<\/span>)<\/span><\/span>\n<\/span>\n# Listowanie plik\u00f3w w katalogu<\/span><\/span>\nfiles = os.listdir(<\/span>"."<\/span>)<\/span><\/span>\nprint<\/span>(<\/span>"<\/span>\\n<\/span>Pliki w katalogu:"<\/span>)<\/span><\/span>\nfor<\/span> file <\/span>in<\/span> files:<\/span><\/span>\n    <\/span>if<\/span> os.path.isfile(file):<\/span><\/span>\n        <\/span>print<\/span>(<\/span>f<\/span>"- <\/span>{<\/span>file<\/span>}<\/span>"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Obs\u0142uga b\u0142\u0119d\u00f3w przy pracy z plikami:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    try<\/span>:<\/span><\/span>\n    <\/span>with<\/span> <\/span>open<\/span>(<\/span>"nieistniejacy.txt"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n        content = file.read()<\/span><\/span>\nexcept<\/span> <\/span>FileNotFoundError<\/span>:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"Plik nie istnieje!"<\/span>)<\/span><\/span>\nexcept<\/span> <\/span>PermissionError<\/span>:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"Brak uprawnie\u0144 do odczytu pliku!"<\/span>)<\/span><\/span>\nexcept<\/span> <\/span>Exception<\/span> <\/span>as<\/span> e:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Wyst\u0105pi\u0142 b\u0142\u0105d: <\/span>{<\/span>e<\/span>}<\/span>"<\/span>)<\/span><\/span>\n<\/span>\n# Bezpieczne sprawdzanie przed otwarciem<\/span><\/span>\nimport<\/span> os<\/span><\/span>\n<\/span>\nfilename = <\/span>"dane.txt"<\/span><\/span>\nif<\/span> os.path.exists(filename):<\/span><\/span>\n    <\/span>with<\/span> <\/span>open<\/span>(filename, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n        content = file.read()<\/span><\/span>\n        <\/span>print<\/span>(content)<\/span><\/span>\nelse<\/span>:<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Plik <\/span>{<\/span>filename<\/span>}<\/span> nie istnieje"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Praca z plikami JSON:<\/h4>\n\n\n\n
    <\/path><\/path><\/svg><\/span>
    import<\/span> json<\/span><\/span>\n<\/span>\n# Dane do zapisania<\/span><\/span>\ndata = {<\/span><\/span>\n    <\/span>"name"<\/span>: <\/span>"Jan Kowalski"<\/span>,<\/span><\/span>\n    <\/span>"age"<\/span>: <\/span>30<\/span>,<\/span><\/span>\n    <\/span>"city"<\/span>: <\/span>"Warszawa"<\/span>,<\/span><\/span>\n    <\/span>"hobbies"<\/span>: [<\/span>"programowanie"<\/span>, <\/span>"czytanie"<\/span>, <\/span>"sport"<\/span>]<\/span><\/span>\n}<\/span><\/span>\n<\/span>\n# Zapisywanie do pliku JSON<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"dane.json"<\/span>, <\/span>"w"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    json.dump(data, file, <\/span>indent<\/span>=<\/span>4<\/span>)<\/span><\/span>\n<\/span>\nprint<\/span>(<\/span>"Dane zosta\u0142y zapisane do pliku JSON!"<\/span>)<\/span><\/span>\n<\/span>\n# Czytanie z pliku JSON<\/span><\/span>\nwith<\/span> <\/span>open<\/span>(<\/span>"dane.json"<\/span>, <\/span>"r"<\/span>) <\/span>as<\/span> file:<\/span><\/span>\n    loaded_data = json.load(file)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>"<\/span>\\n<\/span>Wczytane dane:"<\/span>)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Imi\u0119: <\/span>{<\/span>loaded_data[<\/span>'name'<\/span>]<\/span>}<\/span>"<\/span>)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Wiek: <\/span>{<\/span>loaded_data[<\/span>'age'<\/span>]<\/span>}<\/span>"<\/span>)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Miasto: <\/span>{<\/span>loaded_data[<\/span>'city'<\/span>]<\/span>}<\/span>"<\/span>)<\/span><\/span>\n    <\/span>print<\/span>(<\/span>f<\/span>"Hobby: <\/span>{<\/span>', '<\/span>.join(loaded_data[<\/span>'hobbies'<\/span>])<\/span>}<\/span>"<\/span>)<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Dobre praktyki:<\/h4>\n\n\n\n
      \n
    • Zawsze u\u017cywaj with<\/code> do otwierania plik\u00f3w<\/li>\n\n\n\n
    • Sprawdzaj czy plik istnieje przed pr\u00f3b\u0105 odczytu<\/li>\n\n\n\n
    • Obs\u0142uguj wyj\u0105tki przy pracy z plikami<\/li>\n\n\n\n
    • Zamykaj pliki po u\u017cyciu (automatycznie z with<\/code>)<\/li>\n\n\n\n
    • U\u017cywaj odpowiednich tryb\u00f3w otwierania<\/li>\n<\/ul>\n\n\n\n
      Uwaga:<\/h4>\n\n\n\n
      Przyk\u0142ady z zewn\u0119trznymi bibliotekami (requests, numpy, pandas) nie dzia\u0142aj\u0105 w edytorze online – wymagaj\u0105 instalacji w lokalnym \u015brodowisku Python. Niekt\u00f3re wbudowane modu\u0142y (os, datetime) r\u00f3wnie\u017c mog\u0105 nie dzia\u0142a\u0107 w edytorze online.<\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
      Praca z plikami w Pythonie Python oferuje pot\u0119\u017cne narz\u0119dzia do pracy z plikami. Mo\u017cesz czyta\u0107, zapisywa\u0107 i zarz\u0105dza\u0107 r\u00f3\u017cnymi typami plik\u00f3w. Podstawowe operacje na plikach: U\u017cywamy funkcji open() do otwierania plik\u00f3w: Tryby otwierania plik\u00f3w: Zapisywanie do pliku: Dodawanie do pliku: R\u00f3\u017cne sposoby czytania pliku: Praca z plikami CSV: Sprawdzanie istnienia pliku: Obs\u0142uga b\u0142\u0119d\u00f3w przy pracy […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4,3],"tags":[6,23,5],"class_list":["post-55","post","type-post","status-publish","format-standard","hentry","category-kurs","category-python","tag-kurs","tag-pliki","tag-python"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/posts\/55","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/python-ai.pl\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=55"}],"version-history":[{"count":1,"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/posts\/55\/revisions"}],"predecessor-version":[{"id":56,"href":"https:\/\/python-ai.pl\/index.php?rest_route=\/wp\/v2\/posts\/55\/revisions\/56"}],"wp:attachment":[{"href":"https:\/\/python-ai.pl\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=55"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/python-ai.pl\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=55"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/python-ai.pl\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=55"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}