愛了！這18個 Python 高效編程技巧真香！

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>>>a=3

>>>b=6

>>>a,b=b,a

>>>print(a)
>>>6

>>>ptint(b)
>>>5

>>>?some_list?=?[1,?2,?3,?4,?5]

>>>?another_list?=?[?x?+?1?for?x?in?some_list?]

>>>?another_list
[2,?3,?4,?5,?6]

>>>?#?Set?Comprehensions
>>>?some_list?=?[1,?2,?3,?4,?5,?2,?5,?1,?4,?8]

>>>?even_set?=?{?x?for?x?in?some_list?if?x?%?2?==?0?}

>>>?even_set
set([8,?2,?4])

>>>?#?Dict?Comprehensions

>>>?d?=?{?x:?x?%?2?==?0?for?x?in?range(1,?11)?}

>>>?d
{1:?False,?2:?True,?3:?False,?4:?True,?5:?False,?6:?True,?7:?False,?8:?True,?9:?False,?10:?True}

>>>?my_set?=?{1,?2,?1,?2,?3,?4}

>>>?my_set
set([1,?2,?3,?4])

>>>?from?collections?import?Counter
>>>?c?=?Counter('hello?world')

>>>?c
Counter({'l':?3,?'o':?2,?'?':?1,?'e':?1,?'d':?1,?'h':?1,?'r':?1,?'w':?1})

>>>?c.most_common(2)
[('l',?3),?('o',?2)]

>>>?import?json

>>>?print(json.dumps(data))??#?No?indention
{"status":?"OK",?"count":?2,?"results":?[{"age":?27,?"name":?"Oz",?"lactose_intolerant":?true},?{"age":?29,?"name":?"Joe",?"lactose_intolerant":?false}]}

>>>?print(json.dumps(data,?indent=2))??#?With?indention

{
??"status":?"OK",
??"count":?2,
??"results":?[

????{
??????"age":?27,
??????"name":?"Oz",

??????"lactose_intolerant":?true
????},
????{
??????"age":?29,

??????"name":?"Joe",
??????"lactose_intolerant":?false
????}
??]

}

for?x?in?range(1,101):
????print"fizz"[x%3*len('fizz')::]+"buzz"[x%5*len('buzz')::]?or?x

print?"Hello"?if?True?else?"World"
>>>?Hello

nfc?=?["Packers",?"49ers"]
afc?=?["Ravens",?"Patriots"]
print?nfc?+?afc
>>>?['Packers',?'49ers',?'Ravens',?'Patriots']

print?str(1)?+?"?world"
>>>?1?world

print?`1`?+?"?world"
>>>?1?world

print?1,?"world"
>>>?1?world
print?nfc,?1
>>>?['Packers',?'49ers']?1

x?=?2
if?3?>?x?>?1:
???print?x
>>>?2
if?1??0:
???print?x
>>>?2

nfc?=?["Packers",?"49ers"]
afc?=?["Ravens",?"Patriots"]
for?teama,?teamb?in?zip(nfc,?afc):
?????print?teama?+?"?vs.?"?+?teamb
>>>?Packers?vs.?Ravens
>>>?49ers?vs.?Patriots

teams?=?["Packers",?"49ers",?"Ravens",?"Patriots"]
for?index,?team?in?enumerate(teams):
????print?index,?team
>>>?0?Packers
>>>?1?49ers
>>>?2?Ravens
>>>?3?Patriots

numbers?=?[1,2,3,4,5,6]
even?=?[]
for?number?in?numbers:
????if?number%2?==?0:
????????even.append(number)

numbers?=?[1,2,3,4,5,6]
even?=?[number?for?number?in?numbers?if?number%2?==?0]

teams?=?["Packers",?"49ers",?"Ravens",?"Patriots"]
print?{key:?value?for?value,?key?in?enumerate(teams)}
>>>?{'49ers':?1,?'Ravens':?2,?'Patriots':?3,?'Packers':?0}

items?=?[0]*3
print?items
>>>?[0,0,0]

teams?=?["Packers",?"49ers",?"Ravens",?"Patriots"]
print?",?".join(teams)
>>>?'Packers,?49ers,?Ravens,?Patriots'

data?=?{'user':?1,?'name':?'Max',?'three':?4}
try:
???is_admin?=?data['admin']
except?KeyError:
???is_admin?=?False

data?=?{'user':?1,?'name':?'Max',?'three':?4}
is_admin?=?data.get('admin',?False)

x?=?[1,2,3,4,5,6]
#前3個
print?x[:3]
>>>?[1,2,3]
#中間4個
print?x[1:5]
>>>?[2,3,4,5]
#最后3個
print?x[3:]
>>>?[4,5,6]
#奇數(shù)項
print?x[::2]
>>>?[1,3,5]
#偶數(shù)項
print?x[1::2]
>>>?[2,4,6]

from?collections?import?Counter
print?Counter("hello")
>>>?Counter({'l':?2,?'h':?1,?'e':?1,?'o':?1})

from?itertools?import?combinations
teams?=?["Packers",?"49ers",?"Ravens",?"Patriots"]
for?game?in?combinations(teams,?2):
????print?game
>>>?('Packers',?'49ers')
>>>?('Packers',?'Ravens')
>>>?('Packers',?'Patriots')
>>>?('49ers',?'Ravens')
>>>?('49ers',?'Patriots')
>>>?('Ravens',?'Patriots')

False?=?True
if?False:
???print?"Hello"
else:
???print?"World"
>>>?Hello