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| -rw-r--r-- | zh-cn/python3-cn.html.markdown | 35 |
1 files changed, 16 insertions, 19 deletions
diff --git a/zh-cn/python3-cn.html.markdown b/zh-cn/python3-cn.html.markdown index a490ea40..1f294ebb 100644 --- a/zh-cn/python3-cn.html.markdown +++ b/zh-cn/python3-cn.html.markdown @@ -345,9 +345,9 @@ while x < 4: print(x) x += 1 # x = x + 1 的简写 -# try/except块处理异常状况 +# 用try/except块处理异常状况 try: - # 用raise来抛出异常 + # 用raise抛出异常 raise IndexError("This is an index error") except IndexError as e: pass # pass是无操作，但是应该在这里处理错误 @@ -564,31 +564,28 @@ dir(math) ## 7. 高级用法 #################################################### -# Generators help you make lazy code +# 用生成器(generators)方便地写惰性运算 def double_numbers(iterable): for i in iterable: yield i + i -# A generator creates values on the fly. -# Instead of generating and returning all values at once it creates one in each -# iteration. This means values bigger than 15 wont be processed in -# double_numbers. -# Note range is a generator too. Creating a list 1-900000000 would take lot of -# time to be made -# We use a trailing underscore in variable names when we want to use a name that -# would normally collide with a python keyword +# 生成器只有在需要时才计算下一个值。它们每一次循环只生成一个值，而不是把所有的 +# 值全部算好。这意味着double_numbers不会生成大于15的数字。 +# +# range的返回值也是一个生成器，不然一个1到900000000的列表会花很多时间和内存。 +# +# 如果你想用一个Python的关键字当作变量名，可以加一个下划线来区分。 range_ = range(1, 900000000) -# will double all numbers until a result >=30 found +# 当找到一个 >=30 的结果就会停 for i in double_numbers(range_): print(i) if i >= 30: break -# Decorators -# in this example beg wraps say -# Beg will call say. If say_please is True then it will change the returned -# message +# 装饰器(decorators) +# 这个例子中，beg装饰say +# beg会先调用say。如果返回的say_please为真，beg会改变返回的字符串。 from functools import wraps @@ -613,9 +610,9 @@ print(say()) # Can you buy me a beer? print(say(say_please=True)) # Can you buy me a beer? Please! I am poor :( ``` -## Ready For More? +## 想继续学吗？ -### Free Online +### 线上免费材料（英文） * [Learn Python The Hard Way](http://learnpythonthehardway.org/book/) * [Dive Into Python](http://www.diveintopython.net/) @@ -626,7 +623,7 @@ print(say(say_please=True)) # Can you buy me a beer? Please! I am poor :( * [Python Module of the Week](http://pymotw.com/3/) * [A Crash Course in Python for Scientists](http://nbviewer.ipython.org/5920182) -### Dead Tree +### 书籍（也是英文） * [Programming Python](http://www.amazon.com/gp/product/0596158106/ref=as_li_qf_sp_asin_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596158106&linkCode=as2&tag=homebits04-20) * [Dive Into Python](http://www.amazon.com/gp/product/1441413022/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1441413022&linkCode=as2&tag=homebits04-20) |