Sõne viilutamine¶

Sõnedest on võimalik saada üksikuid elemente [] operaatoriga ja alamsõnede jaoks on tähistus [start:stop:step].

Esimese tähe indeks on sõnes 0 ja viimane indeksil len(string) - 1.

[start] indeks, kust alustada tükeldamist, selle ärajätmisel eeldab Python, et tükeldamine algab algusest
[stop] elemendi indeks, kus peatuda, seda elementi ei arvata vahemikku, ärajätmisel tükeldatakse lõpuni
[step] sammu suurus itereerimisel, vaikimisi on see 1 ning -1 itereerib elemendid tagurpidi


        # no pec


        str1 = "Python String"

        # Single character with slice notation, element at index 3 is excluded.
        print(str1[2:3])  # -> t

        # Notation for getting a single character.
        print(str1[2])  # -> t

        # Use negative numbers to get characters from the end.
        print(str1[-1])  # -> g

        # Range of elements between index 0 and index 2, element at index 2 is excluded
        print(str1[0:2])  # -> Py

        # [start] can be omitted.
        print(str1[:2])  # -> Py

        # [stop] can be omitted.
        print(str1[2:])  # -> thon String

        # Range of elements from index 2 to the end.
        print(str1[2:len(str1)])  # -> thon String

        # Last three characters.
        print(str1[-3:])  # -> ing

        # Slicing from start to end, easy way to make a copy.
        print(str1[:])  # -> Python String

        # By choosing [step] to be -1, we get the reverse of original.
        print(str1[::-1])  # -> gnirtS nohtyP

Hea teada: Olemasolevat sõne saab muuta ainult uue sõne loomisega, sest sõne on muutumatu (immutable) andmetüüp.


        # no pec


        aircraft = "Douglas DC-3"
        # Reassigning a new string to variable. The previous value is deleted.
        aircraft = "Hawker Hurricane"
        print(aircraft)  # -> Hawker Hurricane

        supermarine = "Supermarine Spitfire"
        supermarine_new = supermarine[:12] + "Seafire"
        print(supermarine)  # -> Supermarine Spitfire
        print(supermarine_new)  # -> Supermarine Seafire

        supermarine.upper()
        print(supermarine)  # -> Supermarine Spitfire
        supermarine = supermarine.upper()  # Reassigning a new string to variable.
        print(supermarine)  # -> SUPERMARINE SPITFIRE

Soovitatavad liselugemise lingid selgitamaks, mis on muutumatute (immutable) ja muutuvate (mutable) objektide vahe:

Artikkel „Mutable vs Immutable Data Types in Python“
Artikkel „Python Basics: Mutable vs Immutable Objects“