add function

iamjoel · iamjoel · commit 38060580a071 · 2014-10-06T23:09:34.000+08:00
diff --git a/function.py b/function.py
@@ -0,0 +1,99 @@
+#!/usr/bin/python
+#coding:utf-8
+def sayHi():
+    print 'hi';
+
+sayHi();
+
+# 只有在形参表末尾的那些参数可以有默认参数值，
+# 即你不能在声明函数形参的时候，
+# 先声明有默认值的形参而后声明没有默认值的形参。
+def greet(name, word = 'hi'): # word is optional
+    print word + ',' + name;
+
+greet('joel', 'hello');
+greet('jack');
+
+print 10 * '*', '返回值', 10 * '*';
+def returnNone():
+    pass;
+
+print returnNone(); # None
+
+def returnNone2():
+    1 + 3;
+
+print returnNone2(); # None
+
+def returnNone3():
+    return None;
+
+print returnNone3(); # None
+
+def add(a, b):
+    return a + b;
+
+print add(3,5); # 8
+
+
+print 10 * '*', '变量的作用域', 10 * '*';
+x = 3;
+
+def func():
+    x = 5;
+
+func(); # not change global x
+print 'x is still', x; #3
+
+def func2():
+    global x;# tell it's the global x
+    x = 10;
+
+func2(); # change global x
+print 'x change to', x; #10
+
+print 20 * '*';
+x = 0;
+def func3():
+    x = 1;
+    y = 'y~~~';
+    def func4():
+        print x; # 0, global is put before this line
+        global x; # always the outest.
+        x = 2;
+        print y;# can read from outerside
+    print x; #1
+    func4();
+    print x; #1
+
+func3();
+print 'x change to', x; # 2
+
+# 如果你的某个函数有许多参数，
+# 而你只想指定其中的一部分，
+# 那么你可以通过命名来为这些参数赋值——这被称作 关键参数
+# ——我们使用名字（关键字）而不是位置（我们前面所一直使用的方法）来给函数指定实参。
+print 10 * '*', '关键参数', 10 * '*';
+def keyParamFunc(a, b=5, c=10):
+    print 'a is', a, 'and b is', b, 'and c is', c
+
+keyParamFunc(3, 7)
+keyParamFunc(25, c=24)
+keyParamFunc(c=50, a=100)
+
+
+print 10 * '*', '函数文档', 10 * '*';
+def printMax(x, y):
+    '''函数描述： Prints the maximum of two numbers.
+
+    The two values must be integers.'''
+    x = int(x) # convert to integers, if possible
+    y = int(y)
+
+    if x > y:
+        print x, 'is maximum'
+    else:
+        print y, 'is maximum'
+
+printMax(3, 5)
+print printMax.__doc__
diff --git a/loop.py b/loop.py
@@ -5,18 +5,18 @@
 
 for i in range(0,5,2):
     print i;
-print '==============';
+print 20 * '*';
 
 for i in [0, 1, 2]:
     print i;
-print '=====for end =========';
+print 10 * '*', 'for end', 10 * '*';
 
 i =  0;
 while i < 5:
     print i;
     i+=1;
 
-print '==============';
+print 20 * '*';
 
 i =  0;
 while True:
@@ -27,5 +27,3 @@
         if i % 2 == 1:
             continue;
         print i;
-
-print '==============';
diff --git a/string.py b/string.py
@@ -7,6 +7,8 @@
 print "This is the first sentence.\
 This is the second sentence."
 
+print 20 * '*'; # 输出20个*
+
 
 print '''This is a multi-line string. This is the first line.
 This is the second line.
