add new samples

michaelliao · michaelliao · commit 22d92c0de39d · 2015-03-31T13:04:25.000+08:00
diff --git a/.gitignore b/.gitignore
@@ -1,5 +1,8 @@
 *.py[cod]
 
+test.db
+test.txt
+
 # C extensions
 *.so
 
diff --git a/py3/commonlib/do_base64.py b/py3/commonlib/do_base64.py
@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import base64
+
+s = base64.b64encode('在Python中使用BASE 64编码'.encode('utf-8'))
+print(s)
+d = base64.b64decode(s).decode('utf-8')
+print(d)
+
+s = base64.urlsafe_b64encode('在Python中使用BASE 64编码'.encode('utf-8'))
+print(s)
+d = base64.urlsafe_b64decode(s).decode('utf-8')
+print(d)
diff --git a/py3/coroutine/async_hello.py b/py3/coroutine/async_hello.py
@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import asyncio
+
+@asyncio.coroutine
+def hello():
+    print("Hello world!")
+    yield from asyncio.sleep(1)
+    print("Hello again!")
+
+loop = asyncio.get_event_loop()
+loop.run_until_complete(hello())
+loop.close()
diff --git a/py3/db/do_sqlite.py b/py3/db/do_sqlite.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import sqlite3
+
+# 连接到SQLite数据库
+# 数据库文件是test.db
+# 如果文件不存在，会自动在当前目录创建:
+conn = sqlite3.connect('test.db')
+# 创建一个Cursor:
+cursor = conn.cursor()
+# 执行一条SQL语句，创建user表:
+cursor.execute('create table user (id varchar(20) primary key, name varchar(20))')
+# 继续执行一条SQL语句，插入一条记录:
+cursor.execute('insert into user (id, name) values (\'1\', \'Michael\')')
+# 通过rowcount获得插入的行数:
+print('rowcount =', cursor.rowcount)
+# 关闭Cursor:
+cursor.close()
+# 提交事务:
+conn.commit()
+# 关闭Connection:
+conn.close()
+
+# 查询记录：
+conn = sqlite3.connect('test.db')
+cursor = conn.cursor()
+# 执行查询语句:
+cursor.execute('select * from user where id=?', '1')
+# 获得查询结果集:
+values = cursor.fetchall()
+print(values)
+cursor.close()
+conn.close()
diff --git a/py3/debug/do_try.py b/py3/debug/do_try.py
@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+try:
+    print('try...')
+    r = 10 / 0
+    print('result:', r)
+except ZeroDivisionError as e:
+    print('except:', e)
+finally:
+    print('finally...')
+print('END')
diff --git a/py3/functional/decorator.py b/py3/functional/decorator.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import functools
+
+def log(func):
+    @functools.wraps(func)
+    def wrapper(*args, **kw):
+        print('call %s():' % func.__name__)
+        return func(*args, **kw)
+    return wrapper
+
+@log
+def now():
+    print('2015-3-25')
+
+now()
+
+def logger(text):
+    def decorator(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kw):
+            print('%s %s():' % (text, func.__name__))
+            return func(*args, **kw)
+        return wrapper
+    return decorator
+
+@logger('DEBUG')
+def today():
+    print('2015-3-25')
+
+today()
+print(today.__name__)
diff --git a/py3/functional/do_filter.py b/py3/functional/do_filter.py
@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+def is_odd(n):
+    return n % 2 == 1
+
+L = range(100)
+
+print(list(filter(is_odd, L)))
+
+def not_empty(s):
+    return s and s.strip()
+
+print(list(filter(not_empty, ['A', '', 'B', None, 'C', '  '])))
diff --git a/py3/functional/do_partial.py b/py3/functional/do_partial.py
@@ -0,0 +1,9 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import functools
+
+int2 = functools.partial(int, base=2)
+
+print('1000000 =', int2('1000000'))
+print('1010101 =', int2('1010101'))
diff --git a/py3/functional/do_reduce.py b/py3/functional/do_reduce.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from functools import reduce
+
+CHAR_TO_INT = {
+    '0': 0,
+    '1': 1,
+    '2': 2,
+    '3': 3,
+    '4': 4,
+    '5': 5,
+    '6': 6,
+    '7': 7,
+    '8': 8,
+    '9': 9
+}
+
+def str2int(s):
+    ints = map(lambda ch: CHAR_TO_INT[ch], s)
+    return reduce(lambda x, y: x * 10 + y, ints)
+
+print(str2int('0'))
+print(str2int('12300'))
+print(str2int('0012345'))
diff --git a/py3/functional/do_sorted.py b/py3/functional/do_sorted.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from operator import itemgetter
+
+L = ['bob', 'about', 'Zoo', 'Credit']
+
+print(sorted(L))
+print(sorted(L, key=str.lower))
+
+students = [
+    ('Adam', 90),
+    ('Tim', 60),
+    ('Lisa', 80),
+    ('Bart', 60)
+]
+
+print(sorted(students, key=itemgetter(1)))
+
+def student_to_key(t):
+    return '%+02d%s' % (100-t[1], t[0])
+
+print(sorted(students, key=student_to_key))
diff --git a/py3/functional/return_func.py b/py3/functional/return_func.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+def lazy_sum(*args):
+    def sum():
+        ax = 0
+        for n in args:
+            ax = ax + n
+        return ax
+    return sum
+
+f = lazy_sum(1, 2, 4, 5, 7, 8, 9)
+print(f)
+print(f())
+
+# why f1(), f2(), f3() returns 9, 9, 9 rather than 1, 4, 9?
+def count():
+    fs = []
+    for i in range(1, 4):
+        def f():
+             return i * i
+        fs.append(f)
+    return fs
+
+f1, f2, f3 = count()
+
+print(f1())
+print(f2())
+print(f3())
+
+# fix:
+def count():
+    fs = []
+    def f(n):
+        def j():
+            return n * n
+        return j
+    for i in range(1, 4):
+        fs.append(f(i))
+    return fs
+
+f1, f2, f3 = count()
+
+print(f1())
+print(f2())
+print(f3())
diff --git a/py3/io/file.py b/py3/io/file.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from datetime import datetime
+
+with open('test.txt', 'w') as f:
+    f.write('今天是 ')
+    f.write(datetime.now().strftime('%Y-%m-%d'))
+
+with open('test.txt', 'r') as f:
+    s = f.read()
+    print('open for read...')
+    print(s)
+
+with open('test.txt', 'rb') as f:
+    s = f.read()
+    print('open as binary for read...')
+    print(s)
