【自前python講座】基本的な演算／真偽値／None／文字列／リスト／タプル／集合／辞書について

2 + 3
# 5

2 - 3
# -1

2 * 3
# 6

2 / 3
# 0.6666666666666666

3 / (2 - 1)
# 3.0

2**3
# 8

5 // 2
# 2

5 % 2
# 1

base = 10
height = 5
base, height
# (10, 5)

triangle_area = base * height / 2
triangle_area
# 25.0

trapezoidal_area
# ---------------------------------------------------------------------------
# NameError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1289577273.py in <module>
# ----> 1 trapezoidal_area
#
# NameError: name 'trapezoidal_area' is not defined

2_pi_r
#  File "C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/3060862857.py", line 1
#    2_pi_r
#     ^
# SyntaxError: invalid decimal literal

1 < 3
# True

1 > 3
# False

1 == 3
# False

1 != 3
# True

"a" is "b"
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/2297060732.py:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
#   "a" is "b"
# False

"a" is not "b"
# <>:1: SyntaxWarning: "is not" with a literal. Did you mean "!="?
# <>:1: SyntaxWarning: "is not" with a literal. Did you mean "!="?
# C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/1898745988.py:1: SyntaxWarning: "is not" with a literal. Did you mean "!="?
#   "a" is not "b"
# True

(True + False) / (True + True) 
# 0.5

True == 1, True is 1, False == 0, False is 0
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# <>:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
# C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/883044353.py:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
#   True == 1, True is 1, False == 0, False is 0
# C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/883044353.py:1: SyntaxWarning: "is" with a literal. Did you mean "=="?
#   True == 1, True is 1, False == 0, False is 0
# (True, False, True, False)

None

None is False
# False

None == 0
# False

None is None
# True

None == None
#True

"hello"
# 'hello'

'world'
# 'world'

hello = "hello"
hello + " " + "world"
# 'hello world'

"hello" " " "world"
# 'hello world'

hello - "h"
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/3308442367.py in <module>
# ----> 1 hello - "h"
#
# TypeError: unsupported operand type(s) for -: 'str' and 'str'

hello * 5
# 'hellohellohellohellohello'

hello[1]
# 'e'

a_e = "abcde"
a_e[0], a_e[1], a_e[2], a_e[3], a_e[4]
# ('a', 'b', 'c', 'd', 'e')

a_e[5]
# ---------------------------------------------------------------------------
# IndexError                                Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1358315151.py in <module>
# ----> 1 a_e[5]
#
# IndexError: string index out of range

a_e[-1], a_e[-2], a_e[-3], a_e[-4], a_e[-5]
# ('e', 'd', 'c', 'b', 'a')

a_e[1:3], a_e[3:-1], a_e[1:], a_e[:-3], a_e[1-1 : 4-1]
# ('bc', 'd', 'bcde', 'ab', 'abc')

a_e[-1] = "zzz"
a_e
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/3479971852.py in <module>
# ----> 1 a_e[-1] = "zzz"
#       2 a_e
#
# TypeError: 'str' object does not support item assignment

f"a to e = {a_e}, 10 / 2 = {10 / 2}, 1/3={1/3}"
# 'a to e = abcde, 10 / 2 = 5.0, 1/3=0.3333333333333333'

"""
a
b
c
d
e
"""
# '\na\nb\nc\nd\ne\n'

"""\
a\
b\
c\
d\
e\
"""
# 'abcde'

"a \n b"
# 'a \n b'

print("a \n b")
# a 
#  b

print("C:\Program Files (x86)\NVIDIA Corporation")
#   File "C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/1980184030.py", line 1
#     print("C:\Program Files (x86)\NVIDIA Corporation")
#           ^
# SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 22-23: malformed \N character escape

print("C:\\Program Files (x86)\\NVIDIA Corporation")
# C:\Program Files (x86)\NVIDIA Corporation

print(r"C:\Program Files (x86)\NVIDIA Corporation")
# C:\Program Files (x86)\NVIDIA Corporation

"Python" == "pytHON", "Python".casefold() == "pytHON".casefold()
# (False, True)

"aaa bbb cc d".count("a"), "aaa bbb cc d".count("aa"), "aaa bbb cc d".count("a", 1, 3)

"python".endswith("thon")
True

"pythonpython".find("tho"), "pythonpython".find("zzzz")
# (2, -1)

"-".join(["a", "b", "c"])
# 'a-b-c'

"PYthoN".lower(), "python".lower()
# ('python', 'python')

"aaa aaaabbb caacaca dadaaaad".replace("a", "").replace(" ", "")
# 'bbbcccddd'

"Pen, pinapple, apple, pen".replace("pen", "?")
# 'Pen, pinapple, apple, ?'

"Pen, pinapple, apple, pen".casefold().replace("pen".casefold(), "?")
# '?, pinapple, apple, ?'

"1,2,3".split(",")
# ['1', '2', '3']

"1,2,3".split(",", maxsplit=1)
# ['1', '2,3']

"1,2,,,,,,3".split(",")
# ['1', '2', '', '', '', '', '', '3']

"1 2 3".split()
# ['1', '2', '3']

"   1    2    3 ".split()
# ['1', '2', '3']

"   1-    2  -   -  3- ".split()
# ['1-', '2', '-', '-', '3-']

"python".startswith("thon"), "python".startswith("pyt")
# (False, True)

"pythOn".upper()
# 'PYTHON'

"123".zfill(5), "+あ".zfill(5), 
# ('00123', '+000あ')

a = [0, 1, 2, "a", "b", "c"]
a
# [0, 1, 2, 'a', 'b', 'c']

a[0], a[-1], a[1:4]
# (0, 'c', [1, 2, 'a'])

a + a
# [0, 1, 2, 'a', 'b', 'c', 0, 1, 2, 'a', 'b', 'c']

a * 3
# [0, 1, 2, 'a', 'b', 'c', 0, 1, 2, 'a', 'b', 'c', 0, 1, 2, 'a', 'b', 'c']

b = [0, 1, 2]
b[0] = "a"
b[1] = b[2]
b[2] = b[2]**4
b
# ['a', 2, 16]

c = [0, 1, 2, 3, 4]
c[1:4] = ["a", "b", "c"]
c
# [0, 'a', 'b', 'c', 4]

d0 = [0, 1, 2]
d1 = ["a", "b", "c", "d"]
d = [d0, d1]
d
# [[0, 1, 2], ['a', 'b', 'c', 'd']]

e = ["test", "delete"]
del e[-1]
e
# ['test']

del e
e
# ---------------------------------------------------------------------------
# NameError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/2743830455.py in <module>
#       1 del e
# ----> 2 e
#
# NameError: name 'e' is not defined

a = []
a
# []

z = [1, 2, 3]
a, b, c = z
b
# 2

z = [1,2, [3,4,5,[6]]]
a, b, c = z
c0, c1, c2, c3 = c
c2
# 5

z = [1, 2, 3]
a, b = z
b
# ---------------------------------------------------------------------------
# ValueError                                Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1657746003.py in <module>
#       1 z = [1, 2, 3]
# ----> 2 a, b = z
#      3 b
#
# ValueError: too many values to unpack (expected 2)

z = [1, 2, 3, 4, 5]
a, *b = z
b
# [2, 3, 4, 5]

z = [1, 2, 3, 4, 5]
*a, b = z
b
# 5

z = [1, 2, 3, 4, 5]
*a, *b = z
b
#   File "C:\Users\anonymous\AppData\Local\Temp/ipykernel_4472/1964158954.py", line 2
#     *a, *b = z
#     ^
# SyntaxError: two starred expressions in assignment

arr = ["aaa"]
arr.append(1)
arr.append(10)
arr
# ['aaa', 1, 10]

arr = ["aaa"]
arr.extend("b")
arr.extend("ccccccc")
arr.extend(["ddd"])
arr.extend([1000])
arr
# ['aaa', 'b', 'c', 'c', 'c', 'c', 'c', 'c', 'c', 'ddd', 1000]

arr.extend(1000)
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1159857722.py in <module>
# ----> 1 arr.extend(1000)
#
# TypeError: 'int' object is not iterable

arr = ["a", "bb", "ccc", "dddd"]
arr.insert(1, "あ")
arr.insert(-1, 2**8)
arr
# ['a', 'あ', 'bb', 'ccc', 256, 'dddd']

arr = ["a", "bb", "ccc", "dddd"]
arr.remove("a")
arr
# ['bb', 'ccc', 'dddd']

arr = ["a", "bb", "ccc", "dddd"]
arr.remove("b")
arr
# ---------------------------------------------------------------------------
# ValueError                                Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/3654038372.py in <module>
#       1 arr = ["a", "bb", "ccc", "dddd"]
# ----> 2 arr.remove("b")
#       3 arr
# 
# ValueError: list.remove(x): x not in list

arr = ["a", "bb", "ccc", "dddd"]
arr.pop(-1)
arr.pop(0)
arr.pop(0)
arr
# ['ccc']

arr = ["a", "bb", "ccc", "dddd"]
arr.clear()
arr
# []

arr = ["a", "bb", "ccc", "dddd"]
arr.index("bb")
# 1

arr.index("b")
# ---------------------------------------------------------------------------
# ValueError                                Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1344072699.py in <module>
# ----> 1 arr.index("b")
# 
# ValueError: 'b' is not in list

arr = [1, 1, 2, 3, 4, 5, 5, 1, 1, "a"]
arr.count(1)
# 4

arr = [1, 1, 2, 3, 4, 5, 5, 1, 1.00001, 1-1/10000000]
arr.sort()
arr
# [0.9999999, 1, 1, 1, 1.00001, 2, 3, 4, 5, 5]

arr = ["\n", "か", "z", "a", "aaaa", "___", "あ"]
arr.sort()
arr
# ['\n', '___', 'a', 'aaaa', 'z', 'あ', 'か']

arr = [1, "1", 2, 3, 4, 5, 5, 1, 1.00001, 1-1/10000000]
arr.sort()
arr
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/2493599537.py in <module>
#       1 arr = [1, "1", 2, 3, 4, 5, 5, 1, 1.00001, 1-1/10000000]
# ----> 2 arr.sort()
#       3 arr
# 
# TypeError: '<' not supported between instances of 'str' and 'int'

arr = [0, 1, 2, 5, "a", 1000]
arr.reverse()
arr
# [1000, 'a', 5, 2, 1, 0]

1, 2, "a"
# (1, 2, 'a')

(1, 2, "a")
# (1, 2, 'a')

arr = 1,2,"a"
arr
# (1, 2, 'a')

arr = (1)
arr
# 1

arr = (1,)
arr
# (1,)

a = ()
a
# ()

{1, 2, "a", 3, 1, 2, 3, 1, 2, 3, 4, 5, 6, 7}
# {1, 2, 3, 4, 5, 6, 7, 'a'}

txt = "irohanihohetochirinuruo"
set(txt)
# {'a', 'c', 'e', 'h', 'i', 'n', 'o', 'r', 't', 'u'}

arr = [1, 5, 4, 3, 5, 5, (1,3)]
set(arr)
# {(1, 3), 1, 3, 4, 5}

arr = [1, 5, 4, 3, 5, 5, [1,3]]
set(arr)
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/3718866804.py in <module>
#       1 arr = [1, 5, 4, 3, 5, 5, [1,3]]
# ----> 2 set(arr)
# 
# TypeError: unhashable type: 'list'

a = {0, 1, 2, 3, 4,    "a"}
b = {0, 2,       4, 5}
a, b
# ({0, 1, 2, 3, 4, 'a'}, {0, 2, 4, 5})

# union
a | b
# {0, 1, 2, 3, 4, 5, 'a'}

# intersection
a & b
# {0, 2, 4}

# difference
a - b, b - a
# ({1, 3, 'a'}, {5})

# symmetric difference
a ^ b
# {1, 3, 5, 'a'}

a = {"a": 0, "b": 1, "c": 2}
a
# {'a': 0, 'b': 1, 'c': 2}

a["a"], a.get("c")
# (0, 2)

a = {"a": 0, "b": 1, "c": {"c0": 0, "c1": 0}}
a["c"], a["c"]["c1"]
# ({'c0': 0, 'c1': 0}, 0)

a = {"a": 0, "b": 1, "c": 2}
a[0]
# ---------------------------------------------------------------------------
# KeyError                                  Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/1728541355.py in <module>
#       1 a = {"a": 0, "b": 1, "c": 2}
# ----> 2 a[0]
# 
# KeyError: 0

a = {"aaaa": 0, "b": 1, "c": 2, "aaaa": 3, "aaaa": {"memo": "overwritten"}}
a
# {'aaaa': {'memo': 'overwritten'}, 'b': 1, 'c': 2}

z = {"z": 0}
z["zz"] = 1
z["zzz"] = 2
z["z"] = -100
z
# {'z': -100, 'zz': 1, 'zzz': 2}

a = {"a": 0, "b": 1, "c": 2}
keys = a.keys()
keys
# dict_keys(['a', 'b', 'c'])

keys[0]
# ---------------------------------------------------------------------------
# TypeError                                 Traceback (most recent call last)
# ~\AppData\Local\Temp/ipykernel_4472/4009037613.py in <module>
# ----> 1 keys[0]
# 
# TypeError: 'dict_keys' object is not subscriptable

keys_list = list(keys)
keys_list
# ['a', 'b', 'c']

keys_list[0]
# 'a'

a = {"a": 0, "b": 1, "c": 2}
a.values()
# dict_values([0, 1, 2])

list(a.values())
# [0, 1, 2]

a = {"a": 0, "b": 1, "c": 2}
a.items()
# dict_items([('a', 0), ('b', 1), ('c', 2)])

list(a.items())[-1]
# ('c', 2)

z = {"z": 0}
z.setdefault("zz", 1)
z.setdefault("zzz", 2)
z.setdefault("z", -100)
z
# {'z': 0, 'zz': 1, 'zzz': 2}

x = {"00": 0, "01": 1, "02": 2}
y = {"00": "00", "001": 1, "02": 20}
x.update(y)
x
# {'00': '00', '01': 1, '02': 20, '001': 1}

a = {"a": 0, "b": 1, "c": 2}
popped = a.pop("a")
popped, a
# (0, {'b': 1, 'c': 2})

a = {"a": 0, "b": 1, "c": 2}
popped = a.popitem()
popped, a
# (('c', 2), {'a': 0, 'b': 1})

a = {"a": 0, "b": 1, "c": 2}
a.clear()
a
# {}

a = {"a": 0, "b": 1, "c": 2}
b = a.copy()
b
# {'a': 0, 'b': 1, 'c': 2}

a == b
# True

a = {"a": 0, "b": 1, "c": 2}
aa, ab, ac = a
aa, ab, ac
# ('a', 'b', 'c')

aa, ab, ac = a.keys()
aa, ab, ac
#('a', 'b', 'c')

aa, ab, ac = a.values()
aa, ab, ac
# (0, 1, 2)

a = {"a": 0, "b": 1, "c": 2}
del a["b"], a["c"]
a
# {'a': 0}