18 個(gè) Python 高效編程小技巧，Mark！
↑?關(guān)注 + 星標(biāo)?，每天學(xué)Python新技能
后臺(tái)回復(fù)【大禮包】送你Python自學(xué)大禮包
大家好，我是龍哥！
>>>a=3
>>>b=6
>>>a,b=b,a
>>>print(a)>>>6
>>>ptint(b)>>>5
02 字典推導(dǎo)(Dictionary comprehensions)和集合推導(dǎo)(Set comprehensions)
>>>?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])
03 計(jì)數(shù)時(shí)使用Counter計(jì)數(shù)對(duì)象
>>>?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)]
04 漂亮的打印出JSON
>>>?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
????}
??]
}
寫(xiě)一個(gè)程序，打印數(shù)字1到100，3的倍數(shù)打印“Fizz”來(lái)替換這個(gè)數(shù)，5的倍數(shù)打印“Buzz”，對(duì)于既是3的倍數(shù)又是5的倍數(shù)的數(shù)字打印“FizzBuzz”。
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(gè)
print?x[:3]
>>>?[1,2,3]
#中間4個(gè)
print?x[1:5]
>>>?[2,3,4,5]
#最后3個(gè)
print?x[3:]
>>>?[4,5,6]
#奇數(shù)項(xiàng)
print?x[::2]
>>>?[1,3,5]
#偶數(shù)項(xiàng)
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
推薦閱讀
評(píng)論
圖片
表情