pythonic

a,b = b,a
-------------------

res = []
for i in range(10):
    res.append(i)
代替为 
[x for x in range(10)]
-------------------

if x > 3 and y < 2:
    do 
else:
    do
代替为
condition1 = 'x > 3'
condition1 = 'x > 3'
if condition1 and condition2:
    do 
else:
    do
-------------------

for i in range():
代替为
for k,v in enumerate():
-------------------

序列解包
a = 1, b = [2,3]
代替为
a, *b = [1,2,3]
这里着实没看懂
------------------

str = ['a','b','c']
res = ''
for i in str:
    res += i
代替为 
res = ''.join(str)
------------------

if condition is True / not null:
代替为：
if condition:
------------------

获取字典的元素
dict = {'key':'value'}
dict.get('key')
------------------

a = [1,2,3]
for i in range(len(a)):
    a[i] += 1
代替为
a = map(lambda x : x+1,a)
------------------

def func():
    x = 1
    y = 2
代替为
def func(x=1,y=2):
------------------

占位符 _
------------------
if age > 18 and age < 30:
代替为
if 18 < age < 30:
------------------

if a > 3:
    b = 2
else:
    b = 1
代替为
b = 2 if a > 3 else 1
------------------

if x == 1 or x == 2
代替为
if x in [1,2]
------------------

dict = {x : x**2 for x in range(3)}
------------------

f = open('file.txt')
lines = f.reads()
f.close()
代替为
with open('file.txt') as f:
    lines = f.reads()
------------------

更多的请参考：
https://book.pythontips.com/en/latest/index.html
https://github.com/JeffPaine/beautiful_idiomatic_python