nothin

Author: xy

chapter11/filter.py

@@ -0,0 +1,28 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+__author__ = 'xy'
+
+def filter_(bool_func, seq):
+    filtered_seq = []
+    for eachItem in seq:
+        if bool_func(eachItem):
+            filtered_seq.append(eachItem)
+    return filtered_seq
+
+
+from random import randint
+
+
+def odd(n):
+    return n % 2
+
+
+allNums = []
+for eachNum in range(9):
+    allNums.append(randint(1, 99))
+
+print filter(odd, allNums)
+
+# 第一次改进： print filter(lambda x: x % 2, allNums)
+# 第二次改进：用list-if代替filter  print [n for n in allNums if n%2]
+# 第三次改进： print [n for n in [randint(1, 99) for i in range(9)] if n%2]

chapter11/global.py

@@ -0,0 +1,13 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+__author__ = 'xy'
+
+
+is_this_global = 'xyz'
+def foo():
+    global is_this_global  # 在局部使用全局变量之前先声明gloabl
+    this_is_global = 'abc'
+    is_this_global = 'def'
+    print this_is_global + is_this_global
+
+foo()

chapter11/lambda.py

@@ -0,0 +1,8 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+__author__ = 'xy'
+
+def add(x, y):
+    return x + y
+
+sum = lambda x, y: x + y

chapter11/map.py

@@ -0,0 +1,15 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+__author__ = 'xy'
+
+
+def map_(func, seq):
+    mapped_seq = []
+    for eachItem in seq:
+        mapped_seq.append(func(eachItem))
+    return mapped_seq
+
+
+print map(lambda x: x**2, range(6))
+print map(lambda x, y: x+y, [1, 2], [3, 4])  # 用两个list输入两个参数
+print map(None, [1, 3, 5], [2, 4, 6])  # 功能与zip()相同

chapter11/reduce.py

@@ -0,0 +1,16 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+__author__ = 'xy'
+
+def reduce_(bin_func, seq, init=None):
+    Iseq = list(seq)
+    if init is None:
+        res = Iseq.pop()
+    else:
+        res = init
+    for item in Iseq:
+        res = bin_func(res, item)
+    return res
+
+
+print 'the total is :', reduce((lambda x, y: x+y), range(5))