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author | Geoff Liu <cangming.liu@gmail.com> | 2014-11-04 13:15:57 -0700 |
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committer | Geoff Liu <cangming.liu@gmail.com> | 2014-11-04 13:15:57 -0700 |
commit | ce381ce958b45d5249e597b51703b5ef65247310 (patch) | |
tree | def0a05ec0261909a77dab40d0e2b183e796fe43 /zh-cn | |
parent | 4fb5839edc6100f0029af0d3a082ec4753c86388 (diff) |
Functions section
Diffstat (limited to 'zh-cn')
-rw-r--r-- | zh-cn/python3-cn.html.markdown | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/zh-cn/python3-cn.html.markdown b/zh-cn/python3-cn.html.markdown index 2c1c03f8..a490ea40 100644 --- a/zh-cn/python3-cn.html.markdown +++ b/zh-cn/python3-cn.html.markdown @@ -406,24 +406,22 @@ add(5, 6) # => 印出"x is 5 and y is 6"并且返回11 add(y=6, x=5) # 关键字参数可以用任何顺序 -# You can define functions that take a variable number of -# positional arguments +# 我们可以定义一个可变参数函数 def varargs(*args): return args varargs(1, 2, 3) # => (1, 2, 3) -# You can define functions that take a variable number of -# keyword arguments, as well +# 我们也可以定义一个关键字可变参数函数 def keyword_args(**kwargs): return kwargs -# Let's call it to see what happens +# 我们来看看结果是什么: keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"} -# You can do both at once, if you like +# 这两种可变参数可以混着用 def all_the_args(*args, **kwargs): print(args) print(kwargs) @@ -433,8 +431,7 @@ all_the_args(1, 2, a=3, b=4) prints: {"a": 3, "b": 4} """ -# When calling functions, you can do the opposite of args/kwargs! -# Use * to expand tuples and use ** to expand kwargs. +# 调用可变参数函数时可以做跟上面相反的,用*展开序列,用**展开字典。 args = (1, 2, 3, 4) kwargs = {"a": 3, "b": 4} all_the_args(*args) # equivalent to foo(1, 2, 3, 4) @@ -442,25 +439,25 @@ all_the_args(**kwargs) # equivalent to foo(a=3, b=4) all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4) -# Function Scope +# 函数作用域 x = 5 def setX(num): - # Local var x not the same as global variable x + # 局部作用域的x和全局域的x是不同的 x = num # => 43 print (x) # => 43 def setGlobalX(num): global x print (x) # => 5 - x = num # global var x is now set to 6 + x = num # 现在全局域的x被赋值 print (x) # => 6 setX(43) setGlobalX(6) -# Python has first class functions +# 函数在Python是一等公民 def create_adder(x): def adder(y): return x + y @@ -469,16 +466,14 @@ def create_adder(x): add_10 = create_adder(10) add_10(3) # => 13 -# There are also anonymous functions +# 也有匿名函数 (lambda x: x > 2)(3) # => True -# TODO - Fix for iterables -# There are built-in higher order functions +# 内置的高阶函数 map(add_10, [1, 2, 3]) # => [11, 12, 13] filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7] -# We can use list comprehensions for nice maps and filters -# List comprehension stores the output as a list which can itself be a nested list +# 用列表推导式可以简化映射和过滤。列表推导式的返回值是另一个列表。 [add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] [x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] |