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Python/シーケンス

< Python
関数 Python
シーケンス 		リスト

シーケンス 編集

Pythonでは、複数のオブジェクトを要素として持つオブジェクト（＝コレクション）のうち、整数のインデックスによって要素を参照できるオブジェクトのグループをシーケンス(sequence)と呼びます[1]。 組込み型の代表的なシーケンスは、リスト、タプル、レンジ オブジェクトです[2]。

スライス記法 編集

シーケンスに共通の機能として、スライス記法があります。

スライス記法
for li in (
    [i for i in range(10)],
    (0, 1, 2, 3, 4, 5, 6, 7, 8, 9),
    range(10),
    "0123456789",
    b"0123456789",
):
    print(
        f"""\
{type(li)=}
{li=}
{li[2:]=}
{li[2:6]=}
{li[:6]=}
{li[:]=}
{id(li)=},{id(li[:])=}
{id(li)=},{id(li[:9])=}
{li[1:8:2]=}
{li[1::2]=}
"""
    )
実行結果
type(li)=<class 'list'>
li=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
li[2:]=[2, 3, 4, 5, 6, 7, 8, 9]
li[2:6]=[2, 3, 4, 5]
li[:6]=[0, 1, 2, 3, 4, 5]
li[:]=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
id(li)=23247490610496,id(li[:])=23247489732224
id(li)=23247490610496,id(li[:9])=23247489732224
li[1:8:2]=[1, 3, 5, 7]
li[1::2]=[1, 3, 5, 7, 9]

type(li)=<class 'tuple'>
li=(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
li[2:]=(2, 3, 4, 5, 6, 7, 8, 9)
li[2:6]=(2, 3, 4, 5)
li[:6]=(0, 1, 2, 3, 4, 5)
li[:]=(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
id(li)=23247491653056,id(li[:])=23247491653056
id(li)=23247491653056,id(li[:9])=23247490368448
li[1:8:2]=(1, 3, 5, 7)
li[1::2]=(1, 3, 5, 7, 9)

type(li)=<class 'range'>
li=range(0, 10)
li[2:]=range(2, 10)
li[2:6]=range(2, 6)
li[:6]=range(0, 6)
li[:]=range(0, 10)
id(li)=23247491019616,id(li[:])=23247490390464
id(li)=23247491019616,id(li[:9])=23247490390464
li[1:8:2]=range(1, 8, 2)
li[1::2]=range(1, 10, 2)

type(li)=<class 'str'>
li='0123456789'
li[2:]='23456789'
li[2:6]='2345'
li[:6]='012345'
li[:]='0123456789'
id(li)=23247489812400,id(li[:])=23247489812400
id(li)=23247489812400,id(li[:9])=23247489814704
li[1:8:2]='1357'
li[1::2]='13579'

type(li)=<class 'bytes'>
li=b'0123456789'
li[2:]=b'23456789'
li[2:6]=b'2345'
li[:6]=b'012345'
li[:]=b'0123456789'
id(li)=23247491020288,id(li[:])=23247491020288
id(li)=23247491020288,id(li[:9])=23247490390224
li[1:8:2]=b'1357'
li[1::2]=b'13579'

シーケンス・オブジェクトごとのアトリビュートの有無 編集

組込み関数hasattr(obj, name)を使うと、オブジェクトobjが名前nameな属性を持っているかの検査ができます。

シーケンス・オブジェクトごとのアトリビュートの有無
sequences = (
    [i for i in range(10)],
    (0, 1, 2, 3, 4, 5, 6, 7, 8, 9),
    range(10),
    "0123456789",
    b"0123456789",
    zip([],[]),
)
attrs = set()

for li in sequences:
    for x in dir(li):
        attrs.add(x)

c = 0
for x in sorted(attrs):
    if c % 10 == 0:
        print("Type", ", ".join(str(type(li)) for li in sequences), sep=": ")
    print(x, ", ".join("o" if hasattr(li, x) else "x" for li in sequences), sep=": ")
    c += 1
else:
    print("Type", ", ".join(str(type(li)) for li in sequences), sep=": ")
実行結果
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
__add__: o, o, x, o, o, x
__bool__: x, x, o, x, x, x
__class__: o, o, o, o, o, o
__contains__: o, o, o, o, o, x
__delattr__: o, o, o, o, o, o
__delitem__: o, x, x, x, x, x
__dir__: o, o, o, o, o, o
__doc__: o, o, o, o, o, o
__eq__: o, o, o, o, o, o
__format__: o, o, o, o, o, o
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
__ge__: o, o, o, o, o, o
__getattribute__: o, o, o, o, o, o
__getitem__: o, o, o, o, o, x
__getnewargs__: x, o, x, o, o, x
__gt__: o, o, o, o, o, o
__hash__: o, o, o, o, o, o
__iadd__: o, x, x, x, x, x
__imul__: o, x, x, x, x, x
__init__: o, o, o, o, o, o
__init_subclass__: o, o, o, o, o, o
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
__iter__: o, o, o, o, o, o
__le__: o, o, o, o, o, o
__len__: o, o, o, o, o, x
__lt__: o, o, o, o, o, o
__mod__: x, x, x, o, o, x
__mul__: o, o, x, o, o, x
__ne__: o, o, o, o, o, o
__new__: o, o, o, o, o, o
__next__: x, x, x, x, x, o
__reduce__: o, o, o, o, o, o
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
__reduce_ex__: o, o, o, o, o, o
__repr__: o, o, o, o, o, o
__reversed__: o, x, o, x, x, x
__rmod__: x, x, x, o, o, x
__rmul__: o, o, x, o, o, x
__setattr__: o, o, o, o, o, o
__setitem__: o, x, x, x, x, x
__sizeof__: o, o, o, o, o, o
__str__: o, o, o, o, o, o
__subclasshook__: o, o, o, o, o, o
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
append: o, x, x, x, x, x
capitalize: x, x, x, o, o, x
casefold: x, x, x, o, x, x
center: x, x, x, o, o, x
clear: o, x, x, x, x, x
copy: o, x, x, x, x, x
count: o, o, o, o, o, x
decode: x, x, x, x, o, x
encode: x, x, x, o, x, x
endswith: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
expandtabs: x, x, x, o, o, x
extend: o, x, x, x, x, x
find: x, x, x, o, o, x
format: x, x, x, o, x, x
format_map: x, x, x, o, x, x
fromhex: x, x, x, x, o, x
hex: x, x, x, x, o, x
index: o, o, o, o, o, x
insert: o, x, x, x, x, x
isalnum: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
isalpha: x, x, x, o, o, x
isascii: x, x, x, o, o, x
isdecimal: x, x, x, o, x, x
isdigit: x, x, x, o, o, x
isidentifier: x, x, x, o, x, x
islower: x, x, x, o, o, x
isnumeric: x, x, x, o, x, x
isprintable: x, x, x, o, x, x
isspace: x, x, x, o, o, x
istitle: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
isupper: x, x, x, o, o, x
join: x, x, x, o, o, x
ljust: x, x, x, o, o, x
lower: x, x, x, o, o, x
lstrip: x, x, x, o, o, x
maketrans: x, x, x, o, o, x
partition: x, x, x, o, o, x
pop: o, x, x, x, x, x
remove: o, x, x, x, x, x
replace: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
reverse: o, x, x, x, x, x
rfind: x, x, x, o, o, x
rindex: x, x, x, o, o, x
rjust: x, x, x, o, o, x
rpartition: x, x, x, o, o, x
rsplit: x, x, x, o, o, x
rstrip: x, x, x, o, o, x
sort: o, x, x, x, x, x
split: x, x, x, o, o, x
splitlines: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>
start: x, x, o, x, x, x
startswith: x, x, x, o, o, x
step: x, x, o, x, x, x
stop: x, x, o, x, x, x
strip: x, x, x, o, o, x
swapcase: x, x, x, o, o, x
title: x, x, x, o, o, x
translate: x, x, x, o, o, x
upper: x, x, x, o, o, x
zfill: x, x, x, o, o, x
Type: <class 'list'>, <class 'tuple'>, <class 'range'>, <class 'str'>, <class 'bytes'>, <class 'zip'>

脚註 編集

  1. ^ sequenceと言う型があるわけではありません。
  2. ^ 辞書も3.6以降では順序固定ですが、シーケンスの一種だと考えることは稀です。


  関数 Python
シーケンス 		リスト  
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