DDR爱好者之家 Design By 杰米
Python由于语言的简洁性,让我们以人类思考的方式来写代码,新手更容易上手,老鸟更爱不释手。
要写出 Pythonic(优雅的、地道的、整洁的)代码,还要平时多观察那些大牛代码,Github 上有很多非常优秀的源代码值得阅读,比如:requests、flask、tornado,这里小明收集了一些常见的 Pythonic 写法,帮助你养成写优秀代码的习惯。
01. 变量交换
Bad
tmp = a a = b b = tmp
Pythonic
a,b = b,a
02. 列表推导
Bad
my_list = [] for i in range(10): my_list.append(i*2)
Pythonic
my_list = [i*2 for i in range(10)]
03. 单行表达式
虽然列表推导式由于其简洁性及表达性,被广受推崇。
但是有许多可以写成单行的表达式,并不是好的做法。
Bad
print 'one'; print 'two' if x == 1: print 'one' if <complex comparison> and <other complex comparison>: # do something
Pythonic
print 'one' print 'two' if x == 1: print 'one' cond1 = <complex comparison> cond2 = <other complex comparison> if cond1 and cond2: # do something
04. 带索引遍历
Bad
for i in range(len(my_list)): print(i, "-->", my_list[i])
Pythonic
for i,item in enumerate(my_list): print(i, "-->",item)
05. 序列解包
Pythonic
a, *rest = [1, 2, 3] # a = 1, rest = [2, 3] a, *middle, c = [1, 2, 3, 4] # a = 1, middle = [2, 3], c = 4
06. 字符串拼接
Bad
letters = ['s', 'p', 'a', 'm'] s="" for let in letters: s += let
Pythonic
letters = ['s', 'p', 'a', 'm'] word = ''.join(letters)
07. 真假判断
Bad
if attr == True: print 'True!' if attr == None: print 'attr is None!'
Pythonic
if attr: print 'attr is truthy!' if not attr: print 'attr is falsey!' if attr is None: print 'attr is None!'
08. 访问字典元素
Bad
d = {'hello': 'world'} if d.has_key('hello'): print d['hello'] # prints 'world' else: print 'default_value'
Pythonic
d = {'hello': 'world'} print d.get('hello', 'default_value') # prints 'world' print d.get('thingy', 'default_value') # prints 'default_value' # Or: if 'hello' in d: print d['hello']
09. 操作列表
Bad
a = [3, 4, 5] b = [] for i in a: if i > 4: b.append(i)
Pythonic
a = [3, 4, 5] b = [i for i in a if i > 4] # Or: b = filter(lambda x: x > 4, a)
Bad
a = [3, 4, 5] for i in range(len(a)): a[i] += 3
Pythonic
a = [3, 4, 5] a = [i + 3 for i in a] # Or: a = map(lambda i: i + 3, a)
10. 文件读取
Bad
f = open('file.txt') a = f.read() print a f.close()
Pythonic
with open('file.txt') as f: for line in f: print line
11. 代码续行
Bad
my_very_big_string = """For a long time I used to go to bed early. Sometimes, when I had put out my candle, my eyes would close so quickly that I had not even time to say “I'm going to sleep.”""" from some.deep.module.inside.a.module import a_nice_function, another_nice_function, yet_another_nice_function
Pythonic
my_very_big_string = ( "For a long time I used to go to bed early. Sometimes, " "when I had put out my candle, my eyes would close so quickly " "that I had not even time to say “I'm going to sleep.”" ) from some.deep.module.inside.a.module import ( a_nice_function, another_nice_function, yet_another_nice_function)
12. 显式代码
Bad
def make_complex(*args): x, y = args return dict(**locals())
Pythonic
def make_complex(x, y): return {'x': x, 'y': y}
13. 使用占位符
Pythonic
filename = 'foobar.txt' basename, _, ext = filename.rpartition('.')
14. 链式比较
Bad
if age > 18 and age < 60: print("young man")
Pythonic
if 18 < age < 60: print("young man")
理解了链式比较操作,那么你应该知道为什么下面这行代码输出的结果是 False
> False == False == True False
15. 三目运算
这个保留意见。随使用习惯就好。
Bad
if a > 2: b = 2 else: b = 1 #b = 2
Pythonic
a = 3 b = 2 if a > 2 else 1 #b = 2
参考文档
http://docs.python-guide.org/en/latest/writing/style/
https://foofish.net/idiomatic_part2.html
DDR爱好者之家 Design By 杰米
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
DDR爱好者之家 Design By 杰米
暂无评论...
更新日志
2024年11月27日
2024年11月27日
- 凤飞飞《我们的主题曲》飞跃制作[正版原抓WAV+CUE]
- 刘嘉亮《亮情歌2》[WAV+CUE][1G]
- 红馆40·谭咏麟《歌者恋歌浓情30年演唱会》3CD[低速原抓WAV+CUE][1.8G]
- 刘纬武《睡眠宝宝竖琴童谣 吉卜力工作室 白噪音安抚》[320K/MP3][193.25MB]
- 【轻音乐】曼托凡尼乐团《精选辑》2CD.1998[FLAC+CUE整轨]
- 邝美云《心中有爱》1989年香港DMIJP版1MTO东芝首版[WAV+CUE]
- 群星《情叹-发烧女声DSD》天籁女声发烧碟[WAV+CUE]
- 刘纬武《睡眠宝宝竖琴童谣 吉卜力工作室 白噪音安抚》[FLAC/分轨][748.03MB]
- 理想混蛋《Origin Sessions》[320K/MP3][37.47MB]
- 公馆青少年《我其实一点都不酷》[320K/MP3][78.78MB]
- 群星《情叹-发烧男声DSD》最值得珍藏的完美男声[WAV+CUE]
- 群星《国韵飘香·贵妃醉酒HQCD黑胶王》2CD[WAV]
- 卫兰《DAUGHTER》【低速原抓WAV+CUE】
- 公馆青少年《我其实一点都不酷》[FLAC/分轨][398.22MB]
- ZWEI《迟暮的花 (Explicit)》[320K/MP3][57.16MB]