新增decimal测试

zhanghe06 · zhanghe06 · commit f53c8237436d · 2016-06-02T15:35:52.000+08:00
diff --git a/test/test_decimal.py b/test/test_decimal.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+"""
+@author: zhanghe
+@software: PyCharm
+@file: test_decimal.py
+@time: 16-6-2 下午2:56
+"""
+
+
+from decimal import Decimal
+import json
+
+# float(浮点型[二进制]) 转 decimal(十进制)
+# float 先转 str 再转 decimal
+print Decimal('0.12'), repr(Decimal('0.12'))
+print str(Decimal('0.12')), repr(str(Decimal('0.12')))
+print Decimal(0.00), repr(Decimal(0.00))
+print Decimal(0.12), repr(Decimal(0.12))
+print Decimal(0.12)+Decimal(0.36), repr(Decimal(0.12)+Decimal(0.36))
+
+
+p_info = {
+    'p_name': 'a',
+    'p_price': Decimal('8.12')
+}
+
+print p_info
+# print json.dumps(p_info)  # raise TypeError(repr(o) + " is not JSON serializable")
+
+
+def __default(obj):
+    """
+    支持datetime的json encode
+    TypeError: datetime.datetime(2015, 10, 21, 8, 42, 54) is not JSON serializable
+    :param obj:
+    :return:
+    """
+    if isinstance(obj, Decimal):
+        return str(obj)
+    else:
+        raise TypeError('%r is not JSON serializable' % repr(obj))
+
+print json.dumps(p_info, default=__default)
+
+"""
+# 测试结果：
+0.12 Decimal('0.12')
+0.12 '0.12'
+0 Decimal('0')
+0.11999999999999999555910790149937383830547332763671875 Decimal('0.11999999999999999555910790149937383830547332763671875')
+0.4799999999999999822364316060 Decimal('0.4799999999999999822364316060')
+{'p_price': Decimal('8.12'), 'p_name': 'a'}
+{"p_price": "8.12", "p_name": "a"}
+
+# 订单系统必须采用 Decimal 类型存储, 避免浮点型误差累计产生的效应
+"""
