add datetime, itertools and sax

michaelliao · michaelliao · commit ad0786f71bf9 · 2015-04-01T16:02:28.000+08:00
diff --git a/py3/commonlib/use_datetime.py b/py3/commonlib/use_datetime.py
@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from datetime import datetime, timedelta, timezone
+
+# 获取当前datetime:
+now = datetime.now()
+print('now =', now)
+print('type(now) =', type(now))
+
+# 用指定日期时间创建datetime:
+dt = datetime(2015, 4, 19, 12, 20)
+print('dt =', dt)
+
+# 把datetime转换为timestamp:
+print('datetime -> timestamp:', dt.timestamp())
+
+# 把timestamp转换为datetime:
+t = dt.timestamp()
+print('timestamp -> datetime:', datetime.fromtimestamp(t))
+print('timestamp -> datetime as UTC+0:', datetime.utcfromtimestamp(t))
+
+# 从str读取datetime:
+cday = datetime.strptime('2015-6-1 18:19:59', '%Y-%m-%d %H:%M:%S')
+print('strptime:', cday)
+
+# 把datetime格式化输出:
+print('strftime:', cday.strftime('%a, %b %d %H:%M'))
+
+# 对日期进行加减:
+print('current datetime =', cday)
+print('current + 10 hours =', cday + timedelta(hours=10))
+print('current - 1 day =', cday - timedelta(days=1))
+print('current + 2.5 days =', cday + timedelta(days=2, hours=12))
+
+# 把时间从UTC+0时区转换为UTC+8:
+utc_dt = datetime.utcnow().replace(tzinfo=timezone.utc)
+utc8_dt = utc_dt.astimezone(timezone(timedelta(hours=8)))
+print('UTC+0:00 now =', utc_dt)
+print('UTC+8:00 now =', utc8_dt)
diff --git a/py3/commonlib/use_itertools.py b/py3/commonlib/use_itertools.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import itertools
+
+natuals = itertools.count(1)
+for n in natuals:
+    print(n)
+    if n >= 100:
+        break
+
+cs = itertools.cycle('ABC')
+t = 10
+for c in cs:
+    print(c)
+    t = t - 1
+    if t == 0:
+        break
diff --git a/py3/commonlib/use_sax.py b/py3/commonlib/use_sax.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from xml.parsers.expat import ParserCreate
+
+class DefaultSaxHandler(object):
+    def start_element(self, name, attrs):
+        print('sax:start_element: %s, attrs: %s' % (name, str(attrs)))
+
+    def end_element(self, name):
+        print('sax:end_element: %s' % name)
+
+    def char_data(self, text):
+        print('sax:char_data: %s' % text)
+
+xml = r'''<?xml version="1.0"?>
+<ol>
+    <li><a href="/python">Python</a></li>
+    <li><a href="/ruby">Ruby</a></li>
+</ol>
+'''
+
+handler = DefaultSaxHandler()
+parser = ParserCreate()
+parser.StartElementHandler = handler.start_element
+parser.EndElementHandler = handler.end_element
+parser.CharacterDataHandler = handler.char_data
+parser.Parse(xml)
