Python 常用 PEP8 编码规范详解

# (垂直隐式缩进)对准左括号
foo = long_function_name(var_one, var_two,
    var_three, var_four)

# (悬挂缩进) 一般情况只需多一层缩进
foo = long_function_name(
 var_one, var_two,
 var_three, var_four)

# (悬挂缩进) 但下面情况, 需再加多一层缩进， 和后续的语句块区分开来
def long_function_name(
 var_one, var_two, var_three,
 var_four):
 print(var_one)



# 右括号回退
my_list = [
 1, 2, 3,
 4, 5, 6,
]
result = some_function_that_takes_arguments(
 'a', 'b', 'c',
 'd', 'e', 'f',
)

# 不使用垂直对齐时，第一行不能有参数。
foo = long_function_name(var_one, var_two,
 var_three, var_four)

# 参数的悬挂缩进和后续代码块缩进不能区别。
def long_function_name(
 var_one, var_two, var_three,
 var_four):
 print(var_one)

# 右括号不回退，不推荐
my_list = [
 1, 2, 3,
 4, 5, 6,
 ]

result = some_function_that_takes_arguments(
 'a', 'b', 'c',
 'd', 'e', 'f',
 )

# 无括号续行， 利用反斜杠
with open('/path/to/some/file/you/want/to/read') as file_1, \
 open('/path/to/some/file/being/written', 'w') as file_2:
 file_2.write(file_1.read())

# 括号内续行， 尽量在运算符后再续行
class Rectangle(Blob):

 def __init__(self, width, height,
   color='black', emphasis=None, highlight=0):
 if (width == 0 and height == 0 and
  color == 'red' and emphasis == 'strong' or
  highlight > 100):
  raise ValueError("sorry, you lose")
 if width == 0 and height == 0 and (color == 'red' or
      emphasis is None):
  raise ValueError("I don't think so -- values are %s, %s" %
    (width, height))

# 类的方法定义用单个空行分割，两行空行分割顶层函数和类的定义。
class A(object):
 def method1():
 pass

 def method2():
 pass


def method3():
 pass

# 按模块首字母排序导入, 依此递推
import active
import adidas
import create

# 一行导入多模块
import sys, os, knife

# 不按首字母导入
import create
import active
import beyond

# 单引号和双引号效果一样
name = 'JmilkFan'
name = "Hey Guys!"

spam(ham[1], {eggs: 2})

spam( ham[ 1 ], { eggs: 2 } )

if x == 4: print x, y; x, y = y, x

if x == 4 : print x , y ; x , y = y , x

spam(1)
dct['key'] = lst[index]

spam (1)
dct ['key'] = lst [index]

x = 1
y = 2
long_variable = 3

x  = 1
y  = 2
long_variable = 3

a = b
a or b

# 括号内的操作符不需要空格
name = get_name(age, sex=None, city=Beijing)

# Have to define the param `args(List)`, 
# otherwise will be capture the CLI option when execute `python manage.py server`.
# oslo_config: (args if args is not None else sys.argv[1:])
CONF(args=[], default_config_files=[CONFIG_FILE])

x = x + 1 # Compensate for border

# 多行文档, 首行首字母大写，结尾的 """ 应该单独成行
"""Return a foobang
Optional plotz says to frobnicate the bizbaz first.
"""

# 单行的文档， 结尾的 """ 在同一行。
"""Return a foobang"""

class MyClass(object):
 pass

_name = 'name'

vcenter_connection = ''

MAX_OVERFLOW = ''
TOTAL = 1

# Yes
if foo is not None

# No
if not foo is None

# Yes
def f(x): 
 return 2*x

# No
f = lambda x: 2*x

# Yes (捕获具体异常)
try:
 import platform_specific_module
except ImportError:
 platform_specific_module = None

# No (不要全局捕获)
try:
 import platform_specific_module
except:
 platform_specific_module = None

# Yes
try:
 value = collection[key]
except KeyError:
 return key_not_found(key)
else:
 return handle_value(value)

# No
try:
 return handle_value(collection[key])
except KeyError:
 # 可能会捕捉到 handle_value()中的 KeyError, 而不是 collection 的
 return key_not_found(key)

# Yes
def foo():
 return None

# No
def foo():
 return

# Yes
if foo.startswith('bar'):

# No
if foo[:3] == 'bar':

# Yes
if isinstance(obj, int):

# No
if type(obj) is type(1):

# Yes
if not seq:
 pass
if seq:
 pass

# No
if len(seq):
 pass
if not len(seq):
 pass

# Yes
if greeting:
 pass

# No
if greeting == True
 pass
if greeting is True: # Worse
 pass