4.1. Python WAT?!ΒΆ

a = 'ABCDE'
list(a)
# ['A', 'B', 'C', 'D', 'E']

a = 'ABCDE',
list(a)
# ['ABCDE']

a = ('ABCDE',)
list(a)
# ['ABCDE']

list('ABCDE')
# ['A', 'B', 'C', 'D', 'E']

list('ABCDE',)
# ['A', 'B', 'C', 'D', 'E']

list('ABCDE','asd')
# Traceback (most recent call last):
# TypeError: list expected at most 1 arguments, got 2

CPython 3.7.4:

('a' * 4096) is ('a' * 4096)
# True

('a' * 4097) is ('a' * 4097)
# False

  • More information in OOP String Interning

1 + 1 is 2
# True

0.1 + 0.1 == 0.2
# True

0.1 + 0.2 == 0.3
# False

0.1 + 0.2
# 0.30000000000000004

2.2 * 3.0 == 3.3 * 2.0
# False

for x in ('hello'):
    print(x)
# h
# e
# l
# l
# o

for x in ('hello',):
    print(x)
# hello

for x in 'hello':
    print(x)
# h
# e
# l
# l
# o

for x in 'hello',:
    print(x)
# hello

a = [1, 2, 3]
b = a
c = a.copy()

print(a)  # [1, 2, 3]
print(b)  # [1, 2, 3]
print(c)  # [1, 2, 3]

a.append(4)

print(a)  # [1, 2, 3, 4]
print(b)  # [1, 2, 3, 4]
print(c)  # [1, 2, 3]